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rsync(1)                         User Commands                         rsync(1)

NAME
       rsync - a fast, versatile, local/remote file-copying tool

SYNOPSIS
       Local:
           rsync [OPTION...] SRC... [DEST]

       Access via remote shell:
           Pull:
               rsync [OPTION...] [USER@]HOST:SRC... [DEST]
           Push:
               rsync [OPTION...] SRC... [USER@]HOST:DEST

       Access via rsync daemon:
           Pull:
               rsync [OPTION...] [USER@]HOST::SRC... [DEST]
               rsync [OPTION...] rsync://[USER@]HOST[:PORT]/SRC... [DEST]
           Push:
               rsync [OPTION...] SRC... [USER@]HOST::DEST
               rsync [OPTION...] SRC... rsync://[USER@]HOST[:PORT]/DEST

       Usages  with  just  one  SRC argument and no DEST argument will list the
       source files instead of copying.

       The online version of this manpage (which includes cross-linking of top-
       ics) is available at ]8;;https://download.samba.org/pub/rsync/rsync.1\https://download.samba.org/pub/rsync/rsync.1]8;;\.

DESCRIPTION
       Rsync is a fast and extraordinarily versatile file copying tool.  It can
       copy locally, to/from another host over a remote shell, or to/from a re-
       mote rsync daemon.  It offers a large number  of  options  that  control
       every  aspect  of its behavior and permit very flexible specification of
       the set of files to be copied.  It is famous for its delta-transfer  al-
       gorithm, which reduces the amount of data sent over the network by send-
       ing only the differences between the source files and the existing files
       in  the destination.  Rsync is widely used for backups and mirroring and
       as an improved copy command for everyday use.

       Rsync finds files that need to be transferred using a "quick check"  al-
       gorithm  (by  default) that looks for files that have changed in size or
       in last-modified time.  Any changes in the  other  preserved  attributes
       (as requested by options) are made on the destination file directly when
       the  quick  check indicates that the file's data does not need to be up-
       dated.

       Some of the additional features of rsync are:

       o      support for copying hard and soft links, devices, owners, groups,
              and permissions

       o      exclude and exclude-from options similar to GNU tar

       o      a CVS exclude mode for ignoring the same files that CVS would ig-
              nore

       o      can use any transparent remote shell, including ssh or rsh

       o      does not require super-user privileges

       o      pipelining of file transfers to minimize latency costs

       o      support for anonymous or authenticated rsync daemons  (ideal  for
              mirroring)

GENERAL
       Rsync  copies  files  either to or from a remote host, or locally on the
       current host.  It does not support copying files between  two  different
       remote hosts.

       There are two different ways for rsync to contact a remote system: using
       a remote-shell program as the transport (such as ssh or rsh), or by con-
       tacting an rsync daemon directly via TCP.  The remote-shell transport is
       used whenever the source or destination path contains a single colon (:)
       separator  after  a  host  specification.  In this case, the local rsync
       process uses the remote shell program to start an rsync process  on  the
       remote  system.  The two rsync processes then communicate via the remote
       shell program to accomplish the desired transfers.  In  this  case,  the
       files  that  are accessible on the remote system are those accessible to
       the user ID under  which  the  remote  shell  starts  the  remote  rsync
       process.

       Contacting  an rsync daemon directly happens when the source or destina-
       tion path contains a double colon (::) separator after a host specifica-
       tion, OR when an rsync:// URL is specified.  In this  case,  the  remote
       rsync daemon process will provide access only to specific sets of files,
       called  modules, according to its configuration.  It is also possible to
       contact an rsync daemon via a  remote-shell  transport;  see  the  USING
       RSYNC-DAEMON FEATURES VIA A REMOTE-SHELL CONNECTION section for details.

       As  a  special  case, if a single source argument is specified without a
       destination, the files  are  listed  in  an  output  format  similar  to
       "ls -l".

       If  neither  the  source  or destination path specify a remote host, the
       copy occurs locally (see also the --list-only option).

       Rsync refers to the local side as the client and the remote side as  the
       server.   The server is not to be confused with an rsync daemon.  A dae-
       mon is always a server, but a server can be either a daemon or a remote-
       shell spawned process.  If the transfer is local, then  the  rsync  sub-
       process  which  receives  the contents of the files being transferred is
       the server.

SETUP
       Most Linux distributions include rsync as a  package  that  can  be  in-
       stalled  using the package manager.  If for any reason you need to build
       and install rsync from source, see the file README.md  for  installation
       instructions.

       Once installed, you can use rsync to any machine that you can access via
       a  remote  shell,  or  that  has  an rsync daemon available.  For remote
       transfers, rsync normally uses ssh  for  its  communications.   Alterna-
       tively,  you  can specify any remote shell you like, either by using the
       -e command line option, or by setting the  RSYNC_RSH  environment  vari-
       able.

       Note that rsync must be installed on both the source and destination ma-
       chines.

USAGE
       You use rsync in a similar way to other file-copying commands such as cp
       and  rcp.  You must specify a source and a destination, one of which may
       be remote.

       Perhaps the best way to explain the syntax is with some examples:

           rsync -t *.c foo:src/

       This would transfer all files matching the pattern *.c from the  current
       directory  to the directory src on the machine foo.  If any of the files
       already exist on the remote system then the rsync remote-update protocol
       is used to update the file by sending only the differences in the  data.
       Note  that  the  expansion of wildcards on the command-line (*.c) into a
       list of files is handled by the shell before it runs rsync  and  not  by
       rsync itself (as for other Posix-style programs).

           rsync -avz foo:src/bar /data/tmp

       This  would recursively transfer all files from the directory src/bar on
       the machine foo into the /data/tmp/bar directory on the  local  machine.
       The  files  are transferred in archive mode, which ensures that symbolic
       links, devices, attributes, permissions, ownerships, etc. are  preserved
       in  the  transfer.  Additionally, compression will be used to reduce the
       size of data portions of the transfer.

           rsync -avz foo:src/bar/ /data/tmp

       A trailing slash on the source changes this behavior to  avoid  creating
       an  additional  directory  level at the destination.  You can think of a
       trailing / on a source as meaning "copy the contents of this  directory"
       as  opposed  to  "copy the directory by name", but in both cases the at-
       tributes of the containing directory are transferred to  the  containing
       directory  on  the  destination.   In other words, each of the following
       commands copies the files in the same way, including  their  setting  of
       the attributes of /dest/foo:

           rsync -av /src/foo /dest
           rsync -av /src/foo/ /dest/foo

       Note also that host and module references don't require a trailing slash
       to  copy  the  contents  of the default directory.  For example, both of
       these copy the remote directory's contents into "/dest":

           rsync -av host: /dest
           rsync -av host::module /dest

       You can also use rsync in local-only mode, where  both  the  source  and
       destination  don't have a ':' in the name.  In this case it behaves like
       an improved copy command.

       Finally, you can list all the (listable) modules available from  a  par-
       ticular rsync daemon by leaving off the module name:

           rsync somehost.mydomain.com::

COPYING TO A DIFFERENT NAME
       When  you  want  to copy a directory to a different name, use a trailing
       slash on the source directory to put the contents of the directory  into
       any destination directory you like:

           rsync -ai foo/ bar/

       Rsync  also  has the ability to copy a single file to a destination file
       with a different name.  The rules for this are:

       o      The transfer list must consist of a single item (either a file or
              an empty directory)

       o      The final element of the destination path must not exist as a di-
              rectory

       o      The destination path must not have been specified with a trailing
              slash

       Under those circumstances, rsync will use the specified destination path
       as the filename of the destination (rather than constructing a  filename
       using  the last element of the source path).  It is best to use this id-
       iom only when copying a file, and to use the above trailing-slash  idiom
       when copying a directory.

       The  following example copies the foo.c file as bar.c in the save direc-
       tory (assuming that bar.c isn't a directory):

           rsync -ai src/foo.c save/bar.c

       The single-item copy rule can give unexpected results if a wildcard pat-
       tern for the source yields a single item, and  the  destination,  though
       specified  without  a trailing slash, is intended to be a directory, but
       that directory does not exist.  For example, if src/*.c matches one file
       and save/dir doesn't exist, this will perhaps confusingly name the  des-
       tination file save/dir:

           rsync -ai src/*.c save/dir

       To  prevent such an accident, either make sure the destination directory
       exists or specify the destination path with a trailing slash:

           rsync -ai src/*.c save/dir/

SORTED TRANSFER ORDER
       Rsync always sorts the specified filenames into  its  internal  transfer
       list.   This handles the merging together of the contents of identically
       named directories and makes it easy to remove  duplicate  filenames.  It
       can,  however,  result  in  files being transferred in a different order
       from that specified on the command-line.

       If you need a particular file to be transferred prior  to  another,  the
       only  way to be guaranteed of that is to separate the files into differ-
       ent rsync calls.  If it is sufficient for the destination files  to  ap-
       pear  at  almost  the  same  time, consider using --delay-updates, which
       doesn't affect the sorted transfer order, but does make the final  file-
       updating phase happen much more rapidly.

SECURITY
       Rsync  is  frequently run across a network and with elevated privileges,
       so it is worth thinking about who you are trusting and with what.   This
       section is a practical guide for safe use; the project's SECURITY.md de-
       scribes the full threat model and the per-platform residuals.

   Use an authenticated, encrypted transport
       A plain host:path transfer runs over your remote shell (ssh by default),
       which  authenticates the peer and encrypts the connection -- this is the
       safe default.  A direct daemon connection (host::module or rsync://)  is
       not  encrypted  and  its authentication is comparatively weak, so do not
       send sensitive data across an untrusted network.  Instead tunnel it over
       ssh (see USING RSYNC-DAEMON FEATURES VIA A REMOTE-SHELL  CONNECTION)  or
       wrap  it in TLS with rsync-ssl(1), setting RSYNC_SSL_CA_CERT so that the
       server certificate's chain and hostname are  verified.   When  you  must
       supply  a daemon password non-interactively, put it in a --password-file
       that is readable only by you (mode 600) rather than on the command line.

   Copying from an untrusted sending host
       When receiving from a remote host, rsync takes steps to  ensure  that  a
       corrupted  or  compromised  remote  rsync  process can't cause the local
       rsync process to access files beyond the bounds of what  was  requested.
       Rsync  ensures that the list of files being transferred stays within the
       requested tree, and will abort when a file list contains an absolute  or
       relative  path  that  tries  to escape the top of the transfer.  It also
       verifies that no extra source arguments were added to the  transfer  and
       that the file list obeys the exclude rules that were sent to the sender.

       For  those  who want to be extra careful, it is safest to copy untrusted
       remote files into a dedicated destination directory.  For  example,  in-
       stead of copying into your home directory:

           rsync -aiv host1:dir1 ~

       dedicate a "host1-files" directory to the remote content:

           rsync -aiv host1:dir1 ~/host1-files

       See the --trust-sender option for additional details.

   Copying between case-preserving and case-insensitive filesystems
       Copying  from  case-preserving  to case-insensitive filesystems requires
       caution, because it is possible for the name of a symbolic link to over-
       lap with the name of a file or directory once the case distinctions  are
       removed, which can cause potentially dangerous results such as files be-
       ing  written  outside  the destination directory hierarchy.  If you must
       perform such a copy, either disable symlinks via  --no-links  or  enable
       the  munging  of  symlinks  via --munge-links (and make sure you use the
       right local or remote option).  This does not, however, ensure that  you
       get  a  full  copy of all the files (since that may not be possible when
       the names overlap); a potentially better solution is  to  build  a  safe
       list of filenames and pass it to --files-from.

   Symbolic links
       A  malicious sender can include symlinks that point outside the destina-
       tion tree (for example at /etc/passwd).  Use --safe-links to ignore  any
       symlink  that  points  outside  the  set  of files being transferred, or
       --munge-links to store every symlink in a form that is unusable on  disk
       but recoverable later; --no-links drops symlinks entirely.  See the SYM-
       BOLIC LINKS section for how these interact.

       Separately,  the directory and file paths that you supply on the command
       line -- --backup-dir, --temp-dir, --partial-dir, the  --link-dest/--com-
       pare-dest/--copy-dest  basis directories, --log-file, --files-from/--in-
       clude-from/--exclude-from,         --filter         merge         files,
       --write-batch/--read-batch,  and  the destination itself -- are resolved
       so that a symlink component is followed only when it is owned by you  or
       by  root;  an  attacker-planted  symlink along one of those paths is re-
       fused.  --insecure-links turns that protection off (restoring  the  his-
       torical  follow-any-symlink behaviour); use it only when every directory
       along those paths is trusted, never on a path an unprivileged  user  can
       write.

   Use strong checksums
       Rsync  auto-negotiates the strongest checksum that both ends support, so
       keeping both local and remote rsync versions reasonably current is  usu-
       ally  all that is needed.  You can pin the choice with --checksum-choice
       (--cc, e.g. --cc=sha1 or one of the xxHash variants) or constrain  nego-
       tiation with the RSYNC_CHECKSUM_LIST environment variable; only very old
       peers  fall back to MD4/MD5.  This pre-transfer "does this file need up-
       dating?" checksum is separate from the whole-file  checksum  rsync  nor-
       mally  computes  to verify each transferred file afterward (verification
       is off when --checksum-choice=none is forced).

   Protocol version
       The client and server automatically negotiate the newest  protocol  they
       both  support,  so  a current pair is already using the most recent ver-
       sion; --protocol only forces an  older  version  for  compatibility  and
       should not be used to downgrade a connection.  Avoiding old protocols is
       therefore  a  matter of running a current rsync on both ends (a protocol
       below 30 also forces the weak MD4 authentication digest on a daemon con-
       nection -- see the AUTHENTICATION STRENGTH section of rsyncd.conf(5)).

ADVANCED USAGE
       The syntax for requesting multiple files from a remote host is  done  by
       specifying  additional  remote-host  arguments  in the same style as the
       first, or with the hostname omitted.  For instance, all these work:

           rsync -aiv host:file1 :file2 host:file{3,4} /dest/
           rsync -aiv host::modname/file{1,2} host::modname/extra /dest/
           rsync -aiv host::modname/first ::extra-file{1,2} /dest/

       Note that a daemon connection only supports  accessing  one  module  per
       copy command, so if the start of a follow-up path doesn't begin with the
       modname  of  the  first  path,  it is assumed to be a path in the module
       (such as the extra-file1 & extra-file2 that are grabbed above).

       Because really old versions of rsync (prior  to  3.0.0,  released  March
       2008)  only  allowed  specifying one remote-source argument, some people
       have come to rely on the remote  shell  performing  space  splitting  to
       break  a  single argument into multiple paths. Such unintuitive behavior
       is no longer supported by default, though you can  request  it,  as  de-
       scribed in the next paragraph.  Rsync now (since 3.2.4) passes filenames
       to  a  remote shell in such a way as to preserve the characters you give
       it. Thus, if you ask for a file with spaces in the name, that's what the
       remote rsync looks for:

           rsync -aiv host:'a simple file.pdf' /dest/

       If you use scripts that have been written to manually apply extra  quot-
       ing  to the remote rsync arguments, or to rely on remote argument split-
       ting, you can ask rsync to let your script handle  the  extra  escaping.
       This is done by either adding the --old-args option to the rsync runs in
       the  script  (which  requires a new rsync) or exporting RSYNC_OLD_ARGS=1
       and RSYNC_PROTECT_ARGS=0 (which works with old or new rsync versions).

CONNECTING TO AN RSYNC DAEMON
       An rsync daemon provides a way to give access to one or  more  directory
       hierarchies  on  a system in a controlled way, without having to provide
       shell access to the system.  Each directory hierarchy is called a  "mod-
       ule".   The  names,  directories,  access permissions and so on for each
       module are defined by the rsync daemon configuration file, described  in
       rsyncd.conf(5).   Connections  to an rsync daemon typically use TCP port
       873.  The administrator of the system would  normally  arrange  for  the
       rsync daemon to be running; refer to the STARTING AN RSYNC DAEMON TO AC-
       CEPT CONNECTIONS section below for information on how to do that.

       From  the client point of view, using rsync to access an rsync daemon is
       similar to using it with a remote shell except that:

       o      Use either double-colon syntax or rsync:// URL syntax instead  of
              the single-colon (remote shell) syntax.

       o      The first element of the "path" is actually a module name.

       o      Additional  remote source arguments can use an abbreviated syntax
              that omits the hostname and/or the module name, as  discussed  in
              ADVANCED USAGE.

       o      The  remote daemon may print a "message of the day" when you con-
              nect.

       o      If you specify only the host (with no module or path) then a list
              of accessible modules on the daemon is output.

       o      If you specify a remote source path but no destination, a listing
              of the matching files on the remote daemon is output.

       o      To contact an rsync daemon directly, the --rsh (-e)  option  must
              be  omitted.   If it is used, rsync will use the specified remote
              shell program to start an rsync daemon on the remote system.  See
              the USING RSYNC-DAEMON FEATURES  VIA  A  REMOTE-SHELL  CONNECTION
              section for information on this mode of operation.

       An example that copies all the files in a remote module named "src":

           rsync -av host::src /dest

       Some  modules  on  the remote daemon may require authentication.  If so,
       you will receive a password prompt when you connect.  You can avoid  the
       password  prompt  by  setting the environment variable RSYNC_PASSWORD to
       the password you want to use or using the --password-file option.   This
       may be useful when scripting rsync.

       WARNING:  On  some  systems,  environment  variables  are visible to all
       users.  On those systems using --password-file is recommended.

       You may establish the connection via a web proxy by setting the environ-
       ment variable RSYNC_PROXY to a hostname:port pair pointing to  your  web
       proxy.  Note that your web proxy's configuration must support proxy con-
       nections to port 873.

       You may also establish a daemon connection using a program as a proxy by
       setting  the environment variable RSYNC_CONNECT_PROG to the commands you
       wish to run in place of making a direct socket connection.   The  string
       may  contain  the escape "%H" to represent the hostname specified in the
       rsync command (so use "%%" if you need a single  "%"  in  your  string).
       For example:

           export RSYNC_CONNECT_PROG='ssh proxyhost nc %H 873'
           rsync -av targethost1::module/src/ /dest/
           rsync -av rsync://targethost2/module/src/ /dest/

       The  command specified above uses ssh to run nc (netcat) on a proxyhost,
       which forwards all data to port 873 (the rsync daemon) on the targethost
       (%H).

       Note also that if the RSYNC_SHELL environment variable is set, that pro-
       gram will be used to run the RSYNC_CONNECT_PROG command instead of using
       the default shell of the system() call.

USING RSYNC-DAEMON FEATURES VIA A REMOTE-SHELL CONNECTION
       It is sometimes useful to use various features of an rsync daemon  (such
       as  named  modules) without actually allowing any new socket connections
       into a system, other than what is already required to allow remote-shell
       access.  Rsync supports connecting to a host using a  remote  shell  and
       then spawning a single-use "daemon" server that expects to read its con-
       fig  file  in the home directory of the remote user.  This can be useful
       if you want to encrypt a daemon-style transfer's data.   However,  since
       the  daemon  is  started  by the remote user, you may not be able to use
       features which require root privilege, such as  chroot  or  setting  the
       user ID used by the daemon.  (For another way to encrypt a daemon trans-
       fer,  consider using ssh to tunnel a local port to a remote machine, and
       configure a normal rsync daemon on that remote host to allow connections
       only from "localhost".)

       From the user's perspective, a daemon transfer via a  remote-shell  con-
       nection  uses nearly the same command-line syntax as a normal rsync-dae-
       mon transfer, with the only difference being that  you  must  explicitly
       set  the remote shell program on the command-line with the --rsh=COMMAND
       option. (Setting the RSYNC_RSH in the environment will not turn on  this
       functionality.) For example:

           rsync -av --rsh=ssh host::module /dest

       A  "user@"  prefix  in  front of the host serves two purposes at once in
       this mode: it is the rsync-user value (used to log in to a  module  that
       requires  user-based  authentication) and, by default, it is also passed
       to the remote shell as the login user.  So the simple form

           rsync -av --rsh=ssh user@host::module /dest

       runs ssh -l user host and offers "user" as the rsync-user to the module;
       the two are forced to be the same name.

       If you need the remote-shell (ssh) login to use a  different  name  than
       the  rsync-user, give an explicit '-l' option to ssh in the remote-shell
       command.  When ssh is already told which user to log in as,  rsync  does
       not  add  its  own  '-l', so the "user@" prefix is then used only as the
       rsync-user.  For example, using the short version of the --rsh option:

           rsync -av -e "ssh -l ssh-user" rsync-user@host::module /dest

       Here "ssh-user" is used at the ssh level while "rsync-user" is  used  to
       log in to the "module".

       In  this setup, the daemon is started by the ssh command that is access-
       ing the system (which can be forced via the ~/.ssh/authorized_keys file,
       if desired).  However, when accessing a daemon directly, it needs to  be
       started beforehand.

STARTING AN RSYNC DAEMON TO ACCEPT CONNECTIONS
       In  order to connect to an rsync daemon, the remote system needs to have
       a daemon already running (or it needs to have configured something  like
       inetd  to spawn an rsync daemon for incoming connections on a particular
       port).  For full information on how to start a daemon that will handling
       incoming socket connections, see the  manpage  for  rsyncd.conf(5),  the
       config  file  for the daemon.  The manpage contains the full details for
       how to run the daemon, including stand-alone and inetd configurations.

       If you're using one of the remote-shell  transports  for  the  transfer,
       there is no need to manually start an rsync daemon.

EXAMPLES
       Here are some examples of how rsync can be used.

       To  backup  a  home directory, which consists of large MS Word files and
       mail folders, a per-user cron job can be used that runs this each day:

           rsync -aiz . bkhost:backup/joe/

       To move some files from a remote host to the local host, you could run:

           rsync -aiv --remove-source-files rhost:/tmp/{file1,file2}.c ~/src/

OPTION SUMMARY
       Here is a short summary of the options available in rsync.  Each  option
       also has its own detailed description later in this manpage.

       --verbose, -v            increase verbosity
       --info=FLAGS             fine-grained informational verbosity
       --debug=FLAGS            fine-grained debug verbosity
       --stderr=e|a|c           change stderr output mode (default: errors)
       --quiet, -q              suppress non-error messages
       --no-motd                suppress daemon-mode MOTD
       --checksum, -c           skip based on checksum, not mod-time & size
       --archive, -a            archive mode is -rlptgoD (no -A,-X,-U,-N,-H)
       --no-OPTION              turn off an implied OPTION (e.g. --no-D)
       --recursive, -r          recurse into directories
       --inc-recursive, --i-r   enable incremental recursion
       --no-inc-recursive       disable incremental recursion
       --no-i-r                 same as --no-inc-recursive
       --relative, -R           use relative path names
       --no-implied-dirs        don't send implied directories with --relative
       --backup, -b             make backups (see --suffix & --backup-dir)
       --backup-dir=DIR         make backups into hierarchy based in DIR
       --suffix=SUFFIX          backup suffix (default ~ w/o --backup-dir)
       --update, -u             skip files that are newer on the receiver
       --inplace                update destination files in-place
       --append                 append data onto shorter files
       --append-verify          --append w/old data in file checksum
       --dirs, -d               transfer directories without recursing
       --old-dirs               works like --dirs when talking to old rsync
       --old-d                  same as --old-dirs
       --mkpath                 create destination's missing path components
       --links, -l              copy symlinks as symlinks
       --copy-links, -L         transform symlink into referent file/directory
       --copy-unsafe-links      only "unsafe" symlinks are transformed
       --safe-links             ignore symlinks that point outside the tree
       --insecure-links         follow attacker-owned symlinks in operator paths
       --confine-root=DIR       refuse operator paths resolving outside DIR
       --munge-links            munge symlinks to make them safe & unusable
       --copy-dirlinks, -k      transform symlink to directory into referent directory
       --keep-dirlinks, -K      treat symlinked directory on receiver as directory
       --hard-links, -H         preserve hard links
       --perms, -p              preserve permissions
       --executability, -E      preserve executability
       --chmod=CHMOD            affect file and/or directory permissions
       --acls, -A               preserve ACLs (implies --perms)
       --xattrs, -X             preserve extended attributes
       --owner, -o              preserve owner (super-user only)
       --group, -g              preserve group
       --devices                preserve device files (super-user only)
       --copy-devices           copy device contents as a regular file
       --write-devices          write to devices as files (implies --inplace)
       --specials               preserve special files
       --drop-D                 receiver refuses to create devices/specials
       -D                       same as --devices --specials
       --times, -t              preserve modification times
       --atimes, -U             preserve access (use) times
       --open-noatime           avoid changing the atime on opened files
       --crtimes, -N            preserve create times (newness)
       --omit-dir-times, -O     omit directories from --times
       --omit-link-times, -J    omit symlinks from --times
       --super                  receiver attempts super-user activities
       --fake-super             store/recover privileged attrs using xattrs
       --sparse, -S             turn sequences of nulls into sparse blocks
       --preallocate            allocate dest files before writing them
       --dry-run, -n            perform a trial run with no changes made
       --whole-file, -W         copy files whole (w/o delta-xfer algorithm)
       --no-whole-file, --no-W  use the delta-xfer algorithm
       --checksum-choice=STR    choose the checksum algorithm (aka --cc)
       --one-file-system, -x    don't cross filesystem boundaries
       --block-size=SIZE, -B    force a fixed checksum block-size
       --rsh=COMMAND, -e        specify the remote shell to use
       --rsync-path=PROGRAM     specify the rsync to run on remote machine
       --existing               skip creating new files on receiver
       --ignore-non-existing    skip creating new files on receiver
       --ignore-existing        skip updating files that exist on receiver
       --remove-source-files    sender removes synchronized files (non-directory)
       --del                    an alias for --delete-during
       --delete                 delete extraneous files from dest directories
       --delete-before          receiver deletes before xfer, not during
       --delete-during          receiver deletes during the transfer
       --delete-delay           find deletions during, delete after
       --delete-after           receiver deletes after transfer, not during
       --delete-excluded        also delete excluded files from dest directories
       --ignore-missing-args    ignore missing source arguments without error
       --delete-missing-args    delete missing source arguments from destination
       --ignore-errors          delete even if there are I/O errors
       --force                  force deletion of directories even if not empty
       --max-delete=NUM         don't delete more than NUM files
       --max-size=SIZE          don't transfer any file larger than SIZE
       --min-size=SIZE          don't transfer any file smaller than SIZE
       --max-alloc=SIZE         change a limit relating to memory alloc
       --partial                keep partially transferred files
       --partial-dir=DIR        put a partially transferred file into DIR
       --delay-updates          put all updated files into place at end
       --prune-empty-dirs, -m   prune empty directory chains from file-list
       --numeric-ids            don't map uid/gid values by user/group name
       --usermap=STRING         custom username mapping
       --groupmap=STRING        custom groupname mapping
       --chown=USER:GROUP       simple username/groupname mapping
       --timeout=SECONDS        set I/O timeout in seconds
       --contimeout=SECONDS     set daemon connection timeout in seconds
       --ignore-times, -I       don't skip files that match size and time
       --size-only              skip files that match in size
       --modify-window=NUM, -@  set the accuracy for mod-time comparisons
       --temp-dir=DIR, -T       create temporary files in directory DIR
       --fuzzy, -y              find similar file for basis if no dest file
       --compare-dest=DIR       also compare destination files relative to DIR
       --copy-dest=DIR          ... and include copies of unchanged files
       --link-dest=DIR          hardlink to files in DIR when unchanged
       --compress, -z           compress file data during the transfer
       --compress-choice=STR    choose the compression algorithm (aka --zc)
       --compress-level=NUM     explicitly set compression level (aka --zl)
       --compress-threads=NUM   explicitly set compression threads (aka --zt)
       --skip-compress=LIST     skip compressing files with suffix in LIST
       --cvs-exclude, -C        auto-ignore files in the same way CVS does
       --filter=RULE, -f        add a file-filtering RULE
       -F                       same as --filter='dir-merge /.rsync-filter'
                                repeated: --filter='- .rsync-filter'
       --exclude=PATTERN        exclude files matching PATTERN
       --exclude-from=FILE      read exclude patterns from FILE
       --include=PATTERN        don't exclude files matching PATTERN
       --include-from=FILE      read include patterns from FILE
       --files-from=FILE        read list of source-file names from FILE
       --from0, -0              all *-from/filter files are delimited by 0s
       --old-args               disable the modern argument-protection idiom
       --secluded-args, -s      use the protocol to safely send the arguments
       --trust-sender           trust the remote sender's file list
       --copy-as=USER[:GROUP]   specify user & optional group for the copy
       --address=ADDRESS        bind address for outgoing socket to daemon
       --port=PORT              specify double-colon alternate port number
       --sockopts=OPTIONS       specify custom TCP options
       --blocking-io            use blocking I/O for the remote shell
       --outbuf=N|L|B           set out buffering to None, Line, or Block
       --stats                  give some file-transfer stats
       --8-bit-output, -8       leave high-bit chars unescaped in output
       --human-readable, -h     output numbers in a human-readable format
       --progress               show progress during transfer
       -P                       same as --partial --progress
       --itemize-changes, -i    output a change-summary for all updates
       --remote-option=OPT, -M  send OPTION to the remote side only
       --out-format=FORMAT      output updates using the specified FORMAT
       --log-file=FILE          log what we're doing to the specified FILE
       --log-file-format=FMT    log updates using the specified FMT
       --password-file=FILE     read daemon-access password from FILE
       --early-input=FILE       use FILE for daemon's early exec input
       --list-only              list the files instead of copying them
       --bwlimit=RATE           limit socket I/O bandwidth
       --stop-after=MINS        Stop rsync after MINS minutes have elapsed
       --stop-at=y-m-dTh:m      Stop rsync at the specified point in time
       --fsync                  fsync every written file
       --write-batch=FILE       write a batched update to FILE
       --only-write-batch=FILE  like --write-batch but w/o updating dest
       --read-batch=FILE        read a batched update from FILE
       --protocol=NUM           force an older protocol version to be used
       --iconv=CONVERT_SPEC     request charset conversion of filenames
       --checksum-seed=NUM      set block/file checksum seed (advanced)
       --ipv4, -4               prefer IPv4
       --ipv6, -6               prefer IPv6
       --version, -V            print the version + other info and exit
       --help, -h (*)           show this help (* -h is help only on its own)

       Rsync  can  also be run as a daemon, in which case the following options
       are accepted:

       --daemon                 run as an rsync daemon
       --address=ADDRESS        bind to the specified address
       --bwlimit=RATE           limit socket I/O bandwidth
       --config=FILE            specify alternate rsyncd.conf file
       --dparam=OVERRIDE, -M    override global daemon config parameter
       --no-detach              do not detach from the parent
       --port=PORT              listen on alternate port number
       --log-file=FILE          override the "log file" setting
       --log-file-format=FMT    override the "log format" setting
       --sockopts=OPTIONS       specify custom TCP options
       --verbose, -v            increase verbosity
       --ipv4, -4               prefer IPv4
       --ipv6, -6               prefer IPv6
       --help, -h               show this help (when used with --daemon)

OPTIONS
       Rsync accepts both long (double-dash + word) and  short  (single-dash  +
       letter)  options.   The full list of the available options are described
       below.  If an option can be specified in more than one way, the  choices
       are  comma-separated.   Some  options  only  have  a long variant, not a
       short.

       If the option takes a parameter, the parameter is only listed after  the
       long variant, even though it must also be specified for the short.  When
       specifying  a  parameter,  you  can  either use the form --option=param,
       --option param, -o=param, -o param, or -oparam (the latter  choices  as-
       sume that your option has a short variant).

       The parameter may need to be quoted in some manner for it to survive the
       shell's  command-line  parsing.   Also keep in mind that a leading tilde
       (~) in a pathname is substituted by your shell, so make  sure  that  you
       separate the option name from the pathname using a space (rather than an
       equal sign) if you want the local shell to expand it.

       --help Print a short help page describing the options available in rsync
              and exit.  You can also use -h for --help when it is used without
              any  other  options  or arguments (since otherwise it means --hu-
              man-readable).

       --version, -V
              Print the rsync version plus other info and exit.  When repeated,
              the information is output in a JSON format that is  still  fairly
              readable (client side only).

              The output includes a list of compiled-in capabilities, a list of
              optimizations,  the  default list of checksum algorithms, the de-
              fault list of compression algorithms, the default list of  daemon
              auth  digests,  a  link  to  the  rsync web site, and a few other
              items.

       --verbose, -v
              This option increases the amount of  information  you  are  given
              during the transfer.  By default, rsync works silently.  A single
              -v  will  give  you information about what files are being trans-
              ferred and a brief summary at the end.  Two -v options will  give
              you information on what files are being skipped and slightly more
              information  at the end.  More than two -v options should only be
              used if you are debugging rsync.

              The end-of-run summary tells you the number of bytes sent to  the
              remote  rsync  (which is the receiving side on a local copy), the
              number of bytes received from the remote host,  and  the  average
              bytes per second of the transferred data computed over the entire
              length of the rsync run. The second line shows the total size (in
              bytes), which is the sum of all the file sizes that rsync consid-
              ered  transferring.   It also shows a "speedup" value, which is a
              ratio of the total file size divided by the sum of the  sent  and
              received bytes (which is really just a feel-good bigger-is-better
              number).   Note that these byte values can be made more (or less)
              human-readable by using the --human-readable (or --no-human-read-
              able) options.

              The -v option is equivalent to the setting of  groups  of  --info
              and  --debug  options.  You can choose to use these newer options
              in addition to, or in place of  using  --verbose,  as  any  fine-
              grained  settings  override  the  implied  settings  of -v.  Both
              --info and --debug have help texts available that tells  you  ex-
              actly  what  flags  are  set  for each increase in verbosity (use
              --info=help or --debug=help to see them).

              However, do keep in mind that a daemon's "max verbosity"  setting
              will  limit  how  high the various individual flags can be set on
              the daemon side.  For instance, if the max is 2,  then  any  info
              and/or  debug  flag that is set to a higher value than what would
              be set by -vv will be downgraded to the -vv level in the daemon's
              logging.

       --info=FLAGS
              This option lets you have fine-grained control over the  informa-
              tion output you want to see.  An individual flag name may be fol-
              lowed by a level number, with 0 meaning to silence that output, 1
              being the default output level, and higher numbers increasing the
              output  of that flag (for those that support higher levels).  Use
              --info=help to see all the available flag names, what  they  out-
              put,  and what flag names are added for each increase in the ver-
              bose level.  Some examples:

                  rsync -a --info=progress2 src/ dest/
                  rsync -avv --info=stats2,misc1,flist0 src/ dest/

              Note that --info=name's output is affected  by  the  --out-format
              and  --itemize-changes  (-i) options.  See those options for more
              information on what is output and when.

              This option was added to 3.1.0 (released September 2013),  so  an
              older  rsync  on  the  server  side might reject your attempts at
              fine-grained control.  See also the "max verbosity" caveat  above
              when dealing with a daemon.

       --debug=FLAGS
              This  option  lets  you  have fine-grained control over the debug
              output you want to see.  An individual flag name may be  followed
              by a level number, with 0 meaning to silence that output, 1 being
              the  default output level, and higher numbers increasing the out-
              put of that flag (for those that  support  higher  levels).   Use
              --debug=help  to see all the available flag names, what they out-
              put, and what flag names are added for each increase in the  ver-
              bose level.  Some examples:

                  rsync -avvv --debug=none src/ dest/
                  rsync -avA --del --debug=del2,acl src/ dest/

              Note  that  some  debug  messages  will  only  be output when the
              --stderr=all option is specified, especially those pertaining  to
              I/O and buffer debugging.

              This option is not forwarded by the client to the server side, so
              that  you can specify different debug values for each side of the
              transfer.  This also allows you to specify debug options that are
              only present in one of the rsync versions.  If you want to dupli-
              cate the same option on both sides, using brace expansion  is  an
              easy way to save you some typing.  This works in zsh and bash:

                  rsync -aiv {-M,}--debug=del2 src/ dest/

       --stderr=errors|all|client
              This  option  controls  which  processes  output  to  stderr, and
              whether info messages are output to stderr  rather  than  stdout.
              The  mode strings can be abbreviated down as far as a single let-
              ter.  The 3 possible choices are:

              o      errors - (the default) causes all the rsync  processes  to
                     send  errors directly to stderr, even if the process is on
                     the remote side of the transfer.  Info messages  are  sent
                     to  the client side via the protocol stream.  If stderr is
                     not available (i.e. when directly connecting with a daemon
                     via a socket) errors fall back to being sent via the  pro-
                     tocol stream.

              o      all  -  causes  all  rsync messages (info and error) to be
                     written directly to stderr from all (possible)  processes.
                     This causes stderr to become line-buffered (instead of un-
                     buffered) and eliminates the ability to divide up the info
                     and error messages by file handle.  For those doing debug-
                     ging or using several levels of verbosity, this option can
                     help  to  avoid  clogging  up  the  transfer stream (which
                     should prevent any chance of a deadlock bug hanging things
                     up).  It also allows --debug to enable some extra I/O  re-
                     lated messages.

              o      client  -  causes  all  rsync  messages  to be sent to the
                     client side via the protocol stream.  One  client  process
                     outputs  all messages, with errors on stderr and info mes-
                     sages on stdout.  This was the default in older rsync ver-
                     sions, but can cause error delays when a lot  of  transfer
                     data is ahead of the messages.  If you're pushing files to
                     an  older  rsync,  you  may want to use --stderr=all since
                     that idiom has been around for several releases.

              Rsync also accepts the old --msgs2stderr and --no-msgs2stderr op-
              tions, equivalent to the all and client  settings,  respectively,
              and  uses them when forwarding non-default settings to the remote
              side, in case the remote rsync is an older version.

       --quiet, -q
              This option decreases the amount of  information  you  are  given
              during  the  transfer,  notably  suppressing information messages
              from the remote server.  This  option  is  useful  when  invoking
              rsync from cron.

       --no-motd
              This  option affects the information that is output by the client
              at the start of a daemon transfer.  This suppresses the  message-
              of-the-day  (MOTD)  text, but it also affects the list of modules
              that the daemon sends in response to the "rsync  host::"  request
              (due  to a limitation in the rsync protocol), so omit this option
              if you want to request the list of modules from the daemon.

       --ignore-times, -I
              Normally rsync will skip any files that are already the same size
              and have the same modification timestamp.  This option turns  off
              this "quick check" behavior, causing all files to be updated.

              This  option  can  be confusing compared to --ignore-existing and
              --ignore-non-existing in that that they cause rsync  to  transfer
              fewer  files,  while  this  option  causes rsync to transfer more
              files.

       --size-only
              This modifies rsync's "quick check" algorithm for  finding  files
              that  need  to  be  transferred,  changing it from the default of
              transferring files with either a changed size or a changed  last-
              modified  time  to  just  looking  for files that have changed in
              size.  This is useful when starting to use rsync after using  an-
              other mirroring system which may not preserve timestamps exactly.

       --modify-window=NUM, -@
              When comparing two timestamps, rsync treats the timestamps as be-
              ing equal if they differ by no more than the modify-window value.
              The  default  is  0,  which matches just integer seconds.  If you
              specify a negative value (and the receiver is  at  least  version
              3.1.3, released January 2018) then nanoseconds will also be taken
              into  account.  Specifying 1 is useful for copies to/from MS Win-
              dows FAT filesystems, because FAT represents times with a  2-sec-
              ond  resolution (allowing times to differ from the original by up
              to 1 second).

              If you want all your transfers to default to  comparing  nanosec-
              onds, you can create a ~/.popt file and put these lines in it:

                  rsync alias -a -a@-1
                  rsync alias -t -t@-1

              With that as the default, you'd need to specify --modify-window=0
              (aka  -@0)  to override it and ignore nanoseconds, e.g. if you're
              copying between ext3 and ext4, or if the receiving rsync is older
              than 3.1.3.

       --checksum, -c
              This changes the way rsync checks if the files have been  changed
              and are in need of a transfer.  Without this option, rsync uses a
              "quick  check"  that  (by default) checks if each file's size and
              time of last modification match between the sender and  receiver.
              This option changes this to compare a checksum for each file that
              has  a  matching  size.  Generating the checksums means that both
              sides will expend a lot of disk I/O reading all the data  in  the
              files in the transfer, so this can slow things down significantly
              (and  this  is prior to any reading that will be done to transfer
              changed files)

              The sending side generates its checksums while it  is  doing  the
              file-system  scan  that  builds  the list of the available files.
              The receiver generates its checksums  when  it  is  scanning  for
              changed  files, and will checksum any file that has the same size
              as the corresponding sender's file: files with either  a  changed
              size or a changed checksum are selected for transfer.

              Note  that rsync normally verifies that each transferred file was
              correctly reconstructed on  the  receiving  side  by  checking  a
              whole-file checksum that is generated as the file is transferred,
              but that automatic after-the-transfer verification has nothing to
              do with this option's before-the-transfer "Does this file need to
              be updated?" check.

              The  checksum  used is auto-negotiated between the client and the
              server, but can be overridden using either the  --checksum-choice
              (--cc)  option  or  an  environment variable that is discussed in
              that option's section.

       --archive, -a
              This is equivalent to -rlptgoD.  It is a quick way of saying  you
              want  recursion and want to preserve almost everything.  Be aware
              that it does not  include  preserving  ACLs  (-A),  xattrs  (-X),
              atimes  (-U),  crtimes  (-N),  nor  the finding and preserving of
              hardlinks (-H).

              The only exception to the above equivalence is when  --files-from
              is specified, in which case -r is not implied.

       --no-OPTION
              You may turn off one or more implied options by prefixing the op-
              tion  name  with  "no-".  Not all positive options have a negated
              opposite, but a lot do, including those that can be used to  dis-
              able an implied option (e.g.  --no-D, --no-perms) or have differ-
              ent  defaults  in  various  circumstances  (e.g. --no-whole-file,
              --no-blocking-io, --no-dirs).  Every valid negated option accepts
              both the short and the long option name after  the  "no-"  prefix
              (e.g. --no-R is the same as --no-relative).

              As  an  example, if you want to use --archive (-a) but don't want
              --owner (-o), instead of converting  -a  into  -rlptgD,  you  can
              specify -a --no-o (aka --archive --no-owner).

              The  order of the options is important: if you specify --no-r -a,
              the -r option would end up  being  turned  on,  the  opposite  of
              -a --no-r.   Note  also that the side-effects of the --files-from
              option are NOT positional, as it affects  the  default  state  of
              several  options  and slightly changes the meaning of -a (see the
              --files-from option for more details).

       --recursive, -r
              This tells rsync  to  copy  directories  recursively.   See  also
              --dirs  (-d)  for  an option that allows the scanning of a single
              directory.

              See the --inc-recursive option for a discussion of the  incremen-
              tal recursion for creating the list of files to transfer.

       --inc-recursive, --i-r
              This  option  explicitly enables incremental recursion when scan-
              ning for files, which is enabled by default when using the  --re-
              cursive  option  and both sides of the transfer are running rsync
              3.0.0 (released March 2008) or newer.

              Incremental recursion uses much less memory than non-incremental,
              while also beginning the transfer more quickly (since it  doesn't
              need  to  scan  the  entire  transfer  hierarchy before it starts
              transferring files).  If no recursion is enabled  in  the  source
              files, this option has no effect.

              Some  options  require rsync to know the full file list, so these
              options disable the incremental recursion mode.  These include:

              o      --delete-before (the old default of --delete)

              o      --delete-after

              o      --prune-empty-dirs

              o      --delay-updates

              In  order  to   be   compatible   with   incremental   recursion,
              --delete-during is the default delete mode for --delete.

              One side-effect of incremental recursion is that any missing sub-
              directories  inside  a  recursively-scanned directory are (by de-
              fault) created prior to recursing into the sub-directories.  This
              earlier creation point (compared to a non-incremental  recursion)
              allows  rsync  to then set the modify time of the finished direc-
              tory right away (without having to delay that until  a  bunch  of
              recursive  copying  has finished).  However, these early directo-
              ries don't yet have their completed  mode,  mtime,  or  ownership
              set -- they have more restrictive rights until the subdirectory's
              copying  actually  begins.   This  early-creation  idiom  can  be
              avoided by using the --omit-dir-times option.

              Incremental recursion can be disabled using  the  --no-inc-recur-
              sive (--no-i-r) option.

       --no-inc-recursive, --no-i-r
              Disables  the  incremental recursion algorithm of the --recursive
              option.  This makes rsync scan the full file list before  it  be-
              gins to transfer files.  See --inc-recursive for more info.

       --relative, -R
              Use  relative  paths.  This means that the full path names speci-
              fied on the command line are sent to the server rather than  just
              the  last  parts  of  the filenames.  This is particularly useful
              when you want to send several different directories at  the  same
              time.  For example, this command:

                  rsync -av /foo/bar/baz.c remote:/tmp/

              would  create  a file named baz.c in /tmp/ on the remote machine.
              If instead you used

                  rsync -avR /foo/bar/baz.c remote:/tmp/

              then a file named /tmp/foo/bar/baz.c would be created on the  re-
              mote  machine,  preserving  its full path.  These extra path ele-
              ments are called "implied directories" (i.e. the  "foo"  and  the
              "foo/bar" directories in the above example).

              Rsync  always sends these implied directories as real directories
              in the file list, even if a path element is really a  symlink  on
              the sending side.  This prevents some really unexpected behaviors
              when  copying  the  full path of a file that has a symlink in its
              path.  If you want to duplicate a  server-side  symlink,  include
              both the symlink via its path, and the referent directory via its
              real  path.  If you're dealing with an older rsync on the sending
              side, you may need to use the --no-implied-dirs option.

              It is also possible to limit the amount of path information  that
              is sent as implied directories for each path you specify.  With a
              modern  rsync on the sending side (beginning with 2.6.7, released
              March 2006), you can insert a dot and a  slash  into  the  source
              path, like this:

                  rsync -avR /foo/./bar/baz.c remote:/tmp/

              That  would create /tmp/bar/baz.c on the receiving machine. (Note
              that the dot must be followed by a slash, so "/foo/."  would  not
              be  abbreviated.)  For  older  rsync  versions, you would need to
              change directory to limit the source  path.   For  example,  when
              pushing files:

                  (cd /foo; rsync -avR bar/baz.c remote:/tmp/)

              (Note that the parentheses put the two commands into a sub-shell,
              so that the "cd" command doesn't remain in effect for future com-
              mands.) If you're pulling files from an older rsync, use this id-
              iom (but only for a non-daemon transfer):

                  rsync -avR --rsync-path="cd /foo; rsync" \
                       remote:bar/baz.c /tmp/

       --no-implied-dirs
              This  option  affects  the default behavior of the --relative op-
              tion.  When it is specified, the attributes of the implied direc-
              tories from the source names are not included  in  the  transfer.
              This  means  that the corresponding path elements on the destina-
              tion system are left unchanged if they exist, and any missing im-
              plied directories are created with default attributes.  This even
              allows these implied path elements to have big differences,  such
              as being a symlink to a directory on the receiving side.

              For  instance,  if  a command-line argument or a files-from entry
              told rsync to transfer the file "path/foo/file", the  directories
              "path"  and  "path/foo"  are implied when --relative is used.  If
              "path/foo" is a symlink to "bar" on the destination  system,  the
              receiving  rsync  would ordinarily delete "path/foo", recreate it
              as a directory, and receive the  file  into  the  new  directory.
              With  --no-implied-dirs,  the receiving rsync leaves the existing
              "path/foo" symlink in place and follows it, so the file is  writ-
              ten  through the symlink and ends up in "path/bar".  Note the se-
              curity implication: a pre-existing  in-tree  symlink-to-directory
              on the receiving side will redirect where the file is written, so
              only  use  --no-implied-dirs when you trust the destination's ex-
              isting path elements.  (A symlink whose target is absolute or es-
              capes the destination tree is still refused by  the  secure  path
              resolver  rather  than followed.)  Another way to accomplish this
              link preservation is to use  the  --keep-dirlinks  option  (which
              will  also  affect  symlinks  to  directories  in the rest of the
              transfer).

              When pulling files from an rsync older than 3.0.0  (March  2008),
              you may need to use this option if the sending side has a symlink
              in  the  path you request and you wish the implied directories to
              be transferred as normal directories.

       --backup, -b
              With this option, preexisting destination files  are  renamed  as
              each  file  is  transferred  or deleted (that is, each file to be
              deleted or overwritten gets renamed instead).   You  can  control
              where the backup file goes and what (if any) suffix gets appended
              using the --backup-dir and --suffix options.

              If you don't specify --backup-dir:

              1.     the --omit-dir-times option will be forced on

              2.     the  use  of  --delete (without --delete-excluded), causes
                     rsync to add a "protect" filter-rule for the backup suffix
                     to the end of all your existing filters  that  looks  like
                     this:  -f "P *~".  This rule prevents previously backed-up
                     files from being deleted.

              Note that if you are supplying your own  filter  rules,  you  may
              need  to  manually insert your own exclude/protect rule somewhere
              higher up in the list so that it has a high enough priority to be
              effective (e.g. if your rules specify a trailing inclusion/exclu-
              sion of *, the auto-added rule would never be reached).

       --backup-dir=DIR
              This implies the --backup option, and tells rsync  to  store  all
              backups  in  the specified directory on the receiving side.  This
              can be used for incremental backups.  You can additionally  spec-
              ify  a  backup  suffix  using  the --suffix option (otherwise the
              files backed up in the specified directory will keep their origi-
              nal filenames).

              Note that if you specify a relative path,  the  backup  directory
              will  be  relative  to the destination directory, so you probably
              want to specify either an absolute path or  a  path  that  starts
              with  "../".   If an rsync daemon is the receiver, the backup di-
              rectory cannot go outside the module's path  hierarchy,  so  take
              extra  care not to delete or copy into the backup directory inad-
              vertently.

       --suffix=SUFFIX
              This option allows you to override the default backup suffix used
              with the --backup (-b) option.  The default suffix is a ~  if  no
              --backup-dir was specified, otherwise it is an empty string.

       --update, -u
              This  forces  rsync to skip any files which exist on the destina-
              tion and have a modified time that is newer than the source file.
              (If an existing destination file has a modification time equal to
              the source file's, it will be updated if the  sizes  are  differ-
              ent.)

              Note  that  this does not affect the copying of directories, sym-
              links, or other special files.  Also, a difference of object type
              between the sender and receiver is always considered to be impor-
              tant enough for an update, no matter what date is on the objects.
              For example, if the source has a directory where the  destination
              has  a  file,  the  transfer  would occur regardless of the time-
              stamps.

              This option is a TRANSFER RULE, so don't expect any exclude  side
              effects.

              A  caution  for those that choose to combine --inplace with --up-
              date: an interrupted transfer will leave behind a partial file on
              the receiving side that has a very recent modified time,  so  re-
              running  the  transfer will probably not continue the interrupted
              file.  As such, it is usually best to avoid combining  this  with
              --inplace  unless you have implemented manual steps to handle any
              interrupted in-progress files.

       --inplace
              This option changes how rsync transfers  a  file  when  its  data
              needs  to be updated: instead of the default method of creating a
              new copy of the file and moving it into place  when  it  is  com-
              plete, rsync instead writes the updated data directly to the des-
              tination file.

              This has several effects:

              o      Hard  links  are not broken.  This means the new data will
                     be visible through other hard  links  to  the  destination
                     file.   Moreover,  attempts to copy differing source files
                     onto a multiply-linked destination file will result  in  a
                     "tug  of  war" with the destination data changing back and
                     forth.

              o      In-use binaries cannot be updated (either the OS will pre-
                     vent this from happening,  or  binaries  that  attempt  to
                     swap-in their data will misbehave or crash).

              o      The  file's  data  will be in an inconsistent state during
                     the transfer and will be left that way if the transfer  is
                     interrupted or if an update fails.

              o      A  file  that  rsync  cannot  write  to cannot be updated.
                     While a super user can update  any  file,  a  normal  user
                     needs  to  be granted write permission for the open of the
                     file for writing to be successful.

              o      The efficiency of rsync's delta-transfer algorithm may  be
                     reduced  if some data in the destination file is overwrit-
                     ten before it can be copied to a  position  later  in  the
                     file.   This  does  not  apply  if you use --backup, since
                     rsync is smart enough to use the backup file as the  basis
                     file for the transfer.

              WARNING:  you should not use this option to update files that are
              being accessed by others, so be careful when choosing to use this
              for a copy.

              This option is useful for transferring large  files  with  block-
              based changes or appended data, and also on systems that are disk
              bound,  not network bound.  It can also help keep a copy-on-write
              filesystem snapshot from diverging the entire contents of a  file
              that only has minor changes.

              The  option implies --partial (since an interrupted transfer does
              not delete the file), but conflicts with --partial-dir and  --de-
              lay-updates.

       --append
              This  special  copy  mode is only applicable to update files that
              are known to be growing larger, that is, where any existing  con-
              tent  on  the  receiving side is also known to be the same as the
              content on the sender.  The use of --append can be  dangerous  if
              you  aren't  100%  sure  that  all  the files in the transfer are
              shared, growing files.  You should thus use filter rules  to  en-
              sure that you weed out any files that do not fit this criteria.

              Rsync  updates  these growing file in-place without verifying any
              of the existing content in the file (it only verifies the content
              that it is appending).  Rsync skips any files that exist  on  the
              receiving  side  that are not shorter than the associated file on
              the sending side.  It also skips any  files  whose  size  on  the
              sending  side  gets  shorter  during the send negotiations (rsync
              warns about a "diminished" file when this happens).

              This does not interfere with the updating of a file's non-content
              attributes (e.g.  permissions, ownership,  etc.)  when  the  file
              does  not need to be transferred, nor does it affect the updating
              of any directories or non-regular files.

       --append-verify
              This special copy mode works like --append except  that  all  the
              data in the file is included in the checksum verification, making
              it less efficient but also potentially safer.  This option can be
              dangerous  if  you  aren't  100%  sure  that all the files in the
              transfer are shared, growing files.  See the --append option  for
              more details.

              Note:  prior  to  rsync  3.0.0  (March 2008), the --append option
              worked like --append-verify, so if you are  interacting  with  an
              older  rsync  (or  the transfer is using a protocol prior to 30),
              specifying either append option will initiate an  --append-verify
              transfer.

       --dirs, -d
              Tell the sending side to include any directories that are encoun-
              tered.  Unlike --recursive, a directory's contents are not copied
              unless  the directory name specified is "." or ends with a trail-
              ing slash (e.g.  ".", "dir/.", "dir/", etc.).  Without  this  op-
              tion  or  the --recursive option, rsync will skip all directories
              it encounters (and output a message to that effect for each one).
              If you specify both --dirs  and  --recursive,  --recursive  takes
              precedence.

              The  --dirs  option  is implied by the --files-from option or the
              --list-only option (including an implied  --list-only  usage)  if
              --recursive wasn't specified (so that directories are seen in the
              listing).  Specify --no-dirs (or --no-d) if you want to turn this
              off.

              See also the backward-compatibility helper option --old-dirs.

       --old-dirs, --old-d
              This  backward-compatibility  helper tells rsync to use a hack of
              -r --exclude='/*/*' to get an older remote rsync to list a single
              directory without recursing.

       --mkpath
              Create all missing path components of the destination path.

              By default, rsync will create only the  final  component  of  the
              destination  path  if  it does not exist.  If any other component
              does not exist that is an error, as this can help to  catch  mis-
              takes  in  the destination path specification.  With this option,
              rsync creates all the missing destination-path  components,  just
              as if mkdir -p $DEST_PATH had been run on the receiving side.

              When  specifying  a  destination path, including a trailing slash
              ensures that the whole path is treated as directory names  to  be
              created, even when the file list has a single item. See the COPY-
              ING TO A DIFFERENT NAME section for full details on how rsync de-
              cides  if a final destination-path component should be created as
              a directory or not.

              If you would like the newly-created  destination  directories  to
              match  the  directories  on the sending side, you should be using
              --relative (-R) instead of --mkpath.  For instance, the following
              two commands result in the same destination tree,  but  only  the
              second  command  ensures  that  the  "some/extra/path" components
              match the directories on the sending side:

                  rsync -ai --mkpath host:some/extra/path/*.c some/extra/path/
                  rsync -aiR host:some/extra/path/*.c ./

       --links, -l
              Add symlinks to the transferred files instead of noisily ignoring
              them with a "non-regular file" warning for each  symlink  encoun-
              tered.   You  can alternatively silence the warning by specifying
              --info=nonreg0.

              The default handling of symlinks is to  recreate  each  symlink's
              unchanged value on the receiving side.

              See the SYMBOLIC LINKS section for multi-option info.

       --copy-links, -L
              The  sender  transforms  each symlink encountered in the transfer
              into the referent item, following the symlink chain to  the  file
              or  directory  that it references.  If a symlink chain is broken,
              an error is output and the file is dropped from the transfer.

              This option supersedes any other options that affect symlinks  in
              the transfer, since there are no symlinks left in the transfer.

              This  option does not change the handling of existing symlinks on
              the receiving side.

              See the --keep-dirlinks (-K) if you need a symlink to a directory
              to be treated as a real directory on the receiving side.

              See the SYMBOLIC LINKS section for multi-option info.

       --copy-unsafe-links
              This tells rsync to copy the  referent  of  symbolic  links  that
              point  outside  the  copied  tree.   Absolute  symlinks  are also
              treated like ordinary files, and  so  are  any  symlinks  in  the
              source path itself when --relative is used.

              A  symlink is judged unsafe by a lexical test on its value, with-
              out resolving it on disk.  An absolute or empty target is  always
              unsafe.  A relative target is unsafe if its ".." components would
              climb above the top of the transfer; a ".." that appears anywhere
              other than as a leading prefix (an embedded or trailing "/..") is
              also  treated  as  unsafe.   The  top is set by how the source is
              specified: a trailing slash on the source  (e.g.   "/src/subdir/"
              copied to "/dest/subdir") makes that directory itself the top, so
              a  symlink  may  not  point  above it; without the trailing slash
              (e.g.  "/src/subdir" copied  to  "/dest/")  the  source's  parent
              ("/src")  is  the  top, so "subdir" is a name inside the transfer
              and a relative symlink may point to any other name within it.

              Note that safe symlinks are only copied if --links was also spec-
              ified or implied. The --copy-unsafe-links option has no extra ef-
              fect when combined with --copy-links.

              See the SYMBOLIC LINKS section for multi-option info.

       --safe-links
              This tells the receiving rsync to ignore any  symbolic  links  in
              the  transfer  which point outside the copied tree.  All absolute
              symlinks are also ignored.

              Since this ignoring is happening on the receiving side,  it  will
              still be effective even when the sending side has munged symlinks
              (when  it  is  using  --munge-links).  It also affects deletions,
              since the file being present in the transfer prevents any  match-
              ing  file  on the receiver from being deleted when the symlink is
              deemed to be unsafe and is skipped.

              This option has no effect unless it is combined with --links  (or
              an  option that implies --links such as --archive), because with-
              out --links there will not be any symlinks in the transfer.   Its
              effect is superseded by --copy-unsafe-links.

              Using  this  option in conjunction with --relative may give unex-
              pected results.

              See the SYMBOLIC LINKS section for multi-option info.

       --insecure-links
              By default rsync resolves the directory and file paths  that  the
              operator supplies on the command line with a defensive directory-
              tree  walk that follows a symlink component only when it is owned
              by uid 0 or by the running user, and refuses  one  owned  by  any
              other  user.   This stops an attacker who can write inside one of
              those directories from planting a symlink that redirects a privi-
              leged rsync to a target outside the intended  tree,  while  still
              honouring  the operator's own symlinks.  The rule is the same for
              absolute and relative paths.  This applies to the destination di-
              rectory  and  to  the  parameters  to  the   following   options:
              --backup-dir,  --temp-dir/-T,  --partial-dir, --link-dest, --com-
              pare-dest,     --copy-dest,     --log-file,      --password-file,
              --files-from,   --include-from,  --exclude-from,  --filter  merge
              files, --write-batch and --read-batch.

              --insecure-links turns that defence off, restoring the historical
              behaviour of following any symlink in those paths.  Use  it  only
              when you fully trust every directory along each operator-supplied
              path,  as  it re-exposes the symlink-redirection attacks the walk
              prevents.

              The option is local only: it is not sent to the  remote  side  of
              the  transfer.   A  remote-shell peer that needs the opt-out must
              set it there, e.g.  via --rsync-path), and a daemon never honours
              it -- a daemon that receives --insecure-links from a  client  re-
              fuses  the  request.  A daemon administrator who wants the legacy
              behaviour for a single trusted module sets "insecure links = yes"
              in that module's rsyncd.conf(5) section  instead;  a  client  can
              never enable it.

              See the SYMBOLIC LINKS section for multi-option info.

       --confine-root=DIR
              In  the  default  symlink  mode this bounds where operator option
              paths and paths selected from a --files-from list are allowed  to
              resolve:  one  that ends up outside DIR is refused, even if every
              symlink along it was owned by a  trusted  user.  Explicit  source
              roots  remain  operator-selected  transfer  roots.  The ownership
              walk asks who planted a link; this asks where the path came out.

              DIR must be absolute.  Nothing is confined by default, and --con-
              fine-root=/ is a no-op.

              It exists for a wrapper that serves a restricted directory over a
              remote shell, rrsync being the one shipped here, which passes  it
              automatically  whenever  its  restricted  dir is not "/".  Such a
              wrapper can vet the argv it is handed, but  filter  rules  travel
              over the protocol instead: a client can name a merge file outside
              the  restricted  dir in a dir-merge rule and have the server read
              it in as filter rules.  On a pull that needs neither --delete nor
              any verbosity, because an exclude-only merge (the  "-"  modifier)
              makes  every line a pattern, and the client reads the file's con-
              tents off which of its own names  went  missing.   Confining  the
              open  is  what closes that; a merge file inside DIR keeps working
              as before.

              A daemon ignores this option -- its module directory  is  already
              the  boundary,  and the option arrives in a client-supplied argv,
              so honouring it could only widen the module.

              --insecure-links is refused alongside it.  That opt-out  restores
              the historical open, which skips the walk that enforces the root,
              so the two together would silently mean no confinement at all.

              Like  --drop-D,  it  is  not  forwarded to the remote side: it is
              meant to be applied to one end of a connection by itself.

       --munge-links
              This option affects just one side of the transfer and tells rsync
              to munge symlink values when it is  receiving  files  or  unmunge
              symlink  values  when it is sending files.  "Munging" changes the
              symlink target so that the symlink cannot  be  followed  success-
              fully, but allows the original target of the symlink to be recov-
              ered.  "Unmunging"  reverses  this  process  so  that the symlink
              points to the original target.

              This option can  be  enabled  on  the  server  side  without  the
              client's  knowledge,  such  as in an rsync daemon's configuration
              file or by an option  given  to  the  rrsync  (restricted  rsync)
              script.   When  specified  on the client side, specify the option
              normally if it is the client side that has or  needs  the  munged
              symlinks, or use -M--munge-links to give the option to the server
              when  it  has or needs the munged symlinks.  Note that on a local
              transfer, the client is the sender, so specifying the option  di-
              rectly  unmunges  symlinks while specifying it as a remote option
              munges symlinks.

              This option has no effect when sent to a daemon via  --remote-op-
              tion  because  the daemon configures whether it wants munged sym-
              links via its "munge symlinks" parameter.

              The symlink value is munged or unmunged once it is in the  trans-
              fer, so any option that transforms symlinks into non-symlinks oc-
              curs  prior  to  the  munging/unmunging  except for --safe-links,
              which is a choice that the receiver makes, so it bases its  deci-
              sion  on the munged/unmunged value.  This does mean that if a re-
              ceiver has munging enabled, using  --safe-links  will  cause  all
              symlinks to be ignored (since munging makes them all absolute).

              The  method  that  rsync uses to munge a symlink is to prefix its
              value with the string "/rsyncd-munged/".  This prevents the  link
              from  being used, provided that the /rsyncd-munged directory does
              not exist.  When this option is enabled, rsync will refuse to run
              if that path is a directory or a symlink to a  directory  (though
              it only checks at startup).  See also the "munge-symlinks" python
              script  in  the support directory of the source code for a way to
              munge/unmunge one or more symlinks in-place.

       --copy-dirlinks, -k
              This option causes the sending side to treat a symlink to  a  di-
              rectory  as  though  it were a real directory.  This is useful if
              you don't want symlinks to non-directories  to  be  affected,  as
              they would be using --copy-links.

              Without this option, if the sending side has replaced a directory
              with  a  symlink  to  a directory, the receiving side will delete
              anything that is in the way of the new symlink, including  a  di-
              rectory hierarchy (as long as --force or --delete is in effect).

              See  also --keep-dirlinks for an analogous option for the receiv-
              ing side.

              --copy-dirlinks applies to all symlinks  to  directories  in  the
              source.   If  you want to follow only a few specified symlinks, a
              trick you can use is to pass them as additional source  arguments
              with  a  trailing slash, using --relative to make the paths match
              up right.  For example:

                  rsync -r --relative src/./ src/./follow-me/ dest/

              See the SYMBOLIC LINKS section for multi-option info.

       --keep-dirlinks, -K
              This option causes the receiving side to treat a symlink to a di-
              rectory as though it were  a  real  directory,  but  only  if  it
              matches  a  real directory from the sender.  Without this option,
              the receiver's symlink would be deleted and replaced with a  real
              directory.

              For example, suppose you transfer a directory "foo" that contains
              a  file "file", but on the receiver, "foo" is a symlink to direc-
              tory "bar".  Without --keep-dirlinks, the receiver  deletes  sym-
              link  "foo",  recreates  it as a directory, and receives the file
              into the new directory.  With --keep-dirlinks, the receiver keeps
              the symlink and "file" ends up in "bar".

              One note of caution: if you use --keep-dirlinks, you must  either
              trust  all  the symlinks in the copy, or enable the --munge-links
              option on the receiving side!  If it is possible for an untrusted
              user to create their own symlink to any real directory, the  user
              could then (on a subsequent copy) replace the symlink with a real
              directory  and  affect the content of whatever directory the sym-
              link references.  For backup copies, you  are  better  off  using
              something  like  a bind mount instead of a symlink to modify your
              receiving hierarchy.

              See also --copy-dirlinks for an analogous option for the  sending
              side.

              See the SYMBOLIC LINKS section for multi-option info.

       --hard-links, -H
              This  tells rsync to look for hard-linked files in the source and
              link together the corresponding files on the destination.   With-
              out  this  option, hard-linked files in the source are treated as
              though they were separate files.

              This option does NOT necessarily ensure that the pattern of  hard
              links  on  the  destination  exactly  matches that on the source.
              Cases in which the destination may end up with extra  hard  links
              include the following:

              o      If  the  destination  contains extraneous hard-links (more
                     linking than what is present in the source file list), the
                     copying algorithm will not break  them  explicitly.   How-
                     ever,  if  one  or  more of the paths have content differ-
                     ences, the normal file-update process will break those ex-
                     tra links (unless you are using the --inplace option).

              o      If you specify a --link-dest directory that contains  hard
                     links,  the  linking  of the destination files against the
                     --link-dest files can cause some paths in the  destination
                     to  become linked together due to the --link-dest associa-
                     tions.

              Note that rsync can only detect hard links between files that are
              inside the transfer set.  If rsync updates a file that has  extra
              hard-link connections to files outside the transfer, that linkage
              will  be  broken.  If you are tempted to use the --inplace option
              to avoid this breakage, be very careful that you  know  how  your
              files  are  being  updated  so that you are certain that no unin-
              tended changes happen due to lingering hard links  (and  see  the
              --inplace option for more caveats).

              If  incremental  recursion is active (see --inc-recursive), rsync
              may transfer a missing hard-linked file before it finds that  an-
              other  link  for that contents exists elsewhere in the hierarchy.
              This does not affect the accuracy of  the  transfer  (i.e.  which
              files  are hard-linked together), just its efficiency (i.e. copy-
              ing the data for a new, early copy of  a  hard-linked  file  that
              could  have been found later in the transfer in another member of
              the hard-linked set of files).  One way  to  avoid  this  ineffi-
              ciency is to disable incremental recursion using the --no-inc-re-
              cursive option.

       --perms, -p
              This  option  causes  the  receiving rsync to set the destination
              permissions to be the same as the source permissions.  (See  also
              the --chmod option for a way to modify what rsync considers to be
              the source permissions.)

              When this option is off, permissions are set as follows:

              o      Existing  files (including updated files) retain their ex-
                     isting  permissions,  though  the  --executability  option
                     might change just the execute permission for the file.

              o      New  files  get  their "normal" permission bits set to the
                     source file's permissions masked with the receiving direc-
                     tory's default permissions (either the receiving process's
                     umask, or the permissions specified  via  the  destination
                     directory's  default  ACL),  and  their special permission
                     bits disabled except in the case where a new directory in-
                     herits a setgid bit from its parent directory.

              Thus, when --perms and --executability are both disabled, rsync's
              behavior is the same as that of other file-copy  utilities,  such
              as cp(1) and tar(1).

              In  summary:  to  give  destination  files (both old and new) the
              source permissions, use --perms.  To give new files the  destina-
              tion-default   permissions  (while  leaving  existing  files  un-
              changed), make sure that  the  --perms  option  is  off  and  use
              --chmod=ugo=rwX  (which  ensures that all non-masked bits get en-
              abled).  If you'd care to make this  latter  behavior  easier  to
              type,  you could define a popt alias for it, such as putting this
              line in the file ~/.popt (the following defines  the  -Z  option,
              and  includes  --no-g to use the default group of the destination
              directory):

                  rsync alias -Z --no-p --no-g --chmod=ugo=rwX

              You could then use this new option in a command such as this one:

                  rsync -avZ src/ dest/

              (Caveat: make sure that -a does not follow -Z, or it will  re-en-
              able the two --no-* options mentioned above.)

              Note  that  if  the remote rsync is older than 2.6.7 (March 2006)
              and it is the receiver, the behavior when --perms is off may dif-
              fer from that described above.

       --executability, -E
              This option causes rsync to preserve the executability or non-ex-
              ecutability of regular files when --perms is not enabled.  A reg-
              ular file is considered to be executable if at least one  'x'  is
              turned  on  in  its  permissions.   When  an existing destination
              file's executability  differs  from  that  of  the  corresponding
              source file, rsync modifies the destination file's permissions as
              follows:

              o      To make a file non-executable, rsync turns off all its 'x'
                     permissions.

              o      To make a file executable, rsync turns on each 'x' permis-
                     sion that has a corresponding 'r' permission enabled.

              If --perms is enabled, this option is ignored.

       --acls, -A
              This option causes rsync to update the destination ACLs to be the
              same as the source ACLs.  The option also implies --perms.

              The  source  and destination systems must have compatible ACL en-
              tries for this option to work properly.  See the --fake-super op-
              tion for a way to backup and restore ACLs that are  not  compati-
              ble.

       --xattrs, -X
              This  option  causes rsync to update the destination extended at-
              tributes to be the same as the source ones.

              For systems that support extended-attribute  namespaces,  a  copy
              being done by a super-user copies all namespaces except system.*.
              A  normal  user  only copies the user.* namespace.  To be able to
              backup and restore non-user namespaces as a normal user, see  the
              --fake-super option.

              The  above  name filtering can be overridden by using one or more
              filter options with the x modifier.  When you specify  an  xattr-
              affecting  filter  rule, rsync requires that you do your own sys-
              tem/user filtering, as well as any additional filtering for  what
              xattr  names are copied and what names are allowed to be deleted.
              For example, to skip the system namespace, you could specify:

                  --filter='-x system.*'

              To skip all namespaces except the user namespace, you could spec-
              ify a negated-user match:

                  --filter='-x! user.*'

              To prevent any attributes from being deleted, you could specify a
              receiver-only rule that excludes all names:

                  --filter='-xr *'

              Note that the -X option does not copy rsync's special xattr  val-
              ues  (e.g.  those used by --fake-super) unless you repeat the op-
              tion (e.g. -XX).  This "copy all xattrs" mode cannot be used with
              --fake-super.

       --chmod=CHMOD
              This option tells rsync to  apply  one  or  more  comma-separated
              "chmod"  modes  to  the  permission of the files in the transfer.
              The resulting value is treated as though it were the  permissions
              that  the  sending  side  supplied for the file, which means that
              this option can seem to have  no  effect  on  existing  files  if
              --perms is not enabled.

              In addition to the normal parsing rules specified in the chmod(1)
              manpage,  you can specify an item that should only apply to a di-
              rectory by prefixing it with a  'D',  or  specify  an  item  that
              should  only apply to a file by prefixing it with a 'F'.  For ex-
              ample, the following will ensure that all directories get  marked
              set-gid,  that  no  files are other-writable, that both are user-
              writable and group-writable, and that both have  consistent  exe-
              cutability across all bits:

                  --chmod=Dg+s,ug+w,Fo-w,+X

              Using octal mode numbers is also allowed:

                  --chmod=D2775,F664

              Symbolic permission-copy modes are also allowed, such as g=u, o=g
              or  g-o.  A permission-copy item may copy from one class only (u,
              g or o) and cannot be combined with rwxXst permission letters  in
              the  same item.  Use comma-separated items when you need both be-
              haviours, such as g=o,o=.

              A permission-copy = item also clears the  special  bit  for  each
              destination  class  it updates (u clears setuid, g clears setgid,
              and o clears sticky), matching GNU chmod behaviour.

              It is also legal to specify multiple --chmod options, as each ad-
              ditional option is just appended to the list of changes to make.

              See the --perms and --executability options for how the resulting
              permission value can be applied to the files in the transfer.

       --owner, -o
              This option causes rsync to set the  owner  of  each  destination
              filesystem  object  (file, directory, etc.) to be the same as the
              source object, but only if the receiving rsync is  being  run  as
              the  super-user  (see also the --super and --fake-super options).
              Without this option, the owner of new  and/or  transferred  files
              are set to the invoking user on the receiving side.

              The  preservation  of  ownership will associate matching names by
              default, but may fall back to using the ID number in some circum-
              stances (see also the --numeric-ids option  for  a  full  discus-
              sion).

       --group, -g
              This  option  causes  rsync  to set the group of each destination
              filesystem object (file, directory, etc.) to be the same  as  the
              source  object.   If  the receiving program is not running as the
              super-user (or if --no-super was specified), only groups that the
              invoking user on the receiving side is a member of will  be  pre-
              served.   Without  this  option,  the group is set to the default
              group of the invoking user on the receiving side.

              The preservation of group  information  will  associate  matching
              names  by  default,  but  may fall back to using the ID number in
              some circumstances (see also the --numeric-ids option for a  full
              discussion).

       --devices
              This  option  causes rsync to transfer character and block device
              files to the remote system to recreate these devices.  If the re-
              ceiving rsync is not being run as the super-user, rsync  silently
              skips  creating  the  device  files  (see  also  the  --super and
              --fake-super options).

              By default, rsync generates a "non-regular file" warning for each
              device file encountered when this option is not set.  You can si-
              lence the warning by specifying --info=nonreg0.

       --specials
              This option causes rsync to transfer special files, such as named
              sockets and fifos.  If the receiving rsync is not  being  run  as
              the  super-user,  rsync silently skips creating the special files
              (see also the --super and --fake-super options).

              By default, rsync generates a "non-regular file" warning for each
              special file encountered when this option is not  set.   You  can
              silence the warning by specifying --info=nonreg0.

       -D     The -D option is equivalent to "--devices --specials".

       --drop-D
              This  tells  the receiving rsync to refuse to create device files
              and special files, whatever the transfer requested.  Entries  for
              them  are  skipped  exactly  as if -D had not been used, with the
              usual "non-regular file" warning.

              This differs from --no-D in that it changes only what is created,
              not how the file list is encoded.  --no-D also turns off the rdev
              fields that devices and special files carry on the wire,  so  ap-
              plying  it  to  one end of a connection alone leaves the two ends
              disagreeing about the encoding and the transfer fails.   --drop-D
              can  therefore be added on the receiving side by itself, which is
              what it exists for -- the rrsync wrapper uses it to  stop  a  re-
              stricted directory's clients creating device and special files in
              it.  Nodes already present there are left alone.

              Because it only withholds creation, it has no effect on a sending
              rsync.

              This  option is not forwarded to the remote side, since its whole
              purpose is to be applied to one end of a  connection  by  itself.
              It  therefore  affects  the  rsync  process you give it to and no
              other: on a local copy, or on the receiving end of a --server in-
              vocation such as the one rrsync builds.  To set it  on  a  remote
              receiver  from  the  command  line, send it explicitly with --re-
              mote-option (-M):

                  rsync -av -M--drop-D src/ host:dest/

              Passing a plain --drop-D to a push affects only the local sender,
              where it does nothing.

       --copy-devices
              This tells rsync to treat a device on the sending side as a regu-
              lar file, allowing it to be copied to a normal  destination  file
              (or another device if --write-devices was also specified).

              This option is refused by default by an rsync daemon.

       --write-devices
              This  tells  rsync  to  treat a device on the receiving side as a
              regular file, allowing the writing of file data into a device.

              This option implies the --inplace option.

              Be careful using this,  as  you  should  know  what  devices  are
              present  on  the  receiving side of the transfer, especially when
              running rsync as root.

              This option is refused by default by an rsync daemon.

       --times, -t
              This tells rsync to set the modification times of the destination
              files (including directories, symlinks, devices, etc.) to be  the
              same  as the source files.  Note that if this option is not used,
              the optimization that excludes files that have not been  modified
              cannot  be  effective;  in other words, a missing -t (or -a) will
              cause the next transfer to behave as if  it  used  --ignore-times
              (-I),  causing  all files to be updated. (Although rsync's delta-
              transfer algorithm will make the update fairly efficient  if  the
              files haven't actually changed, you're much better off using -t.)

              If  the  negotiated  protocol is older than 30 -- usually because
              the remote rsync is older than 3.0.0 (March 2008),  but  also  if
              --protocol  forces it -- the range of modification times that can
              be conveyed is restricted.  If you have files  dated  older  than
              1970,  make  sure your rsync executables are upgraded so that the
              full range of dates can be conveyed.

       --atimes, -U
              This tells rsync to set the access (use) times of the destination
              files to the same value as the source files.

              If repeated, it also sets the --open-noatime  option,  which  can
              help  you to make the sending and receiving systems have the same
              access times on the transferred  files  without  needing  to  run
              rsync an extra time after a file is transferred.

       --open-noatime
              This  tells  rsync to open files with the O_NOATIME flag (on sys-
              tems that support it) to avoid changing the access  time  of  the
              files  that  are  being transferred.  If your OS does not support
              the O_NOATIME flag then rsync will silently ignore  this  option.
              Note also that some filesystems are mounted to avoid updating the
              atime on read access even without the O_NOATIME flag being set.

       --crtimes, -N,
              This  tells rsync to set the create times (newness) of the desti-
              nation files to the same value as the source  files.  Your  OS  &
              filesystem must support the setting of arbitrary creation (birth)
              times for this option to be supported.

       --omit-dir-times, -O
              This  tells rsync to omit directories when it is preserving modi-
              fication, access, and create times.  If NFS is sharing the direc-
              tories on the receiving side, it is a good idea to use -O.   This
              option is inferred if you use --backup without --backup-dir.

              This  option  also has the side-effect of avoiding early creation
              of missing sub-directories when incremental recursion is enabled,
              as discussed in the --inc-recursive section.

       --omit-link-times, -J
              This tells rsync to omit symlinks when it is preserving modifica-
              tion, access, and create times.

       --super
              This tells the receiving side to  attempt  super-user  activities
              even  if the receiving rsync wasn't run by the super-user.  These
              activities include: preserving users via the --owner option, pre-
              serving all groups (not just the current user's groups)  via  the
              --group  option,  and  copying  devices via the --devices option.
              This is useful for systems that allow such activities without be-
              ing the super-user, and also for ensuring that you will  get  er-
              rors if the receiving side isn't being run as the super-user.  To
              turn  off  super-user activities, the super-user can use --no-su-
              per.

       --fake-super
              When this option is enabled, rsync simulates  super-user  activi-
              ties  by  saving/restoring  the privileged attributes via special
              extended attributes that are attached to each file  (as  needed).
              This  includes  the  file's owner and group (if it is not the de-
              fault), the file's device info (device & special files  are  cre-
              ated  as empty text files), and any permission bits that we won't
              allow to be set on the real file (e.g. the real file gets  u-s,g-
              s,o-t  for  safety) or that would limit the owner's access (since
              the real super-user can always access/change a file, the files we
              create can always be  accessed/changed  by  the  creating  user).
              This  option also handles ACLs (if --acls was specified) and non-
              user extended attributes (if --xattrs was specified).

              This is a good way to backup data without using a super-user, and
              to store ACLs from incompatible systems.

              The --fake-super option only affects the side where the option is
              used.  To affect the remote side of  a  remote-shell  connection,
              use the --remote-option (-M) option:

                  rsync -av -M--fake-super /src/ host:/dest/

              For  a  local  copy,  this option affects both the source and the
              destination.  If you wish a local copy to enable this option just
              for the destination files, specify -M--fake-super.  If you wish a
              local copy to enable this option just for the source files,  com-
              bine --fake-super with -M--super.

              This option is overridden by both --super and --no-super.

              See also the fake super setting in the daemon's rsyncd.conf file.

       --sparse, -S
              Try to handle sparse files efficiently so they take up less space
              on  the  destination.   This relies on the destination filesystem
              supporting sparse files, that is, files where some parts  of  the
              file  don't have corresponding disk blocks allocated for them be-
              cause they contain all zero bytes.

              If combined with --inplace the file created may not end  up  with
              sparse  blocks  (depending on the filesystem type and kernel ver-
              sion), unless the --whole-file option is also  in  effect.   Note
              that  versions  of rsync older than 3.1.3 (January 2018) will re-
              ject the combination of --sparse and --inplace.

       --preallocate
              This tells the receiver to allocate each destination file to  its
              eventual  size  before writing data to the file.  Rsync will only
              use the real filesystem-level preallocation support  provided  by
              Linux's  fallocate(2) system call or Cygwin's posix_fallocate(3),
              not the slow glibc implementation that writes a  null  byte  into
              each block.

              Without  this option, larger files may not be entirely contiguous
              on the filesystem, but with this option rsync will probably  copy
              more  slowly.   If  the  destination  is not an extent-supporting
              filesystem (such as ext4, xfs, NTFS, etc.), this option may  have
              no positive effect at all.

              If  combined with --sparse, the file will only have sparse blocks
              (as opposed to allocated sequences of null bytes) if  the  kernel
              version  and  filesystem type support creating holes in the allo-
              cated data.

       --dry-run, -n
              This makes rsync perform  a  trial  run  that  doesn't  make  any
              changes,  and  produces mostly the same output as a real run.  It
              is most commonly used in  combination  with  the  --verbose  (-v)
              and/or  --itemize-changes  (-i) options to see what an rsync com-
              mand is going to do before one actually runs it.

              The output of --itemize-changes is supposed  to  be  exactly  the
              same  on  a  dry  run and a subsequent real run (barring external
              changes to the source or destination and system  call  failures);
              if  it  isn't,  that's  a bug.  Other output should be mostly un-
              changed, but may differ in some areas.  Notably, a dry  run  does
              not send the actual data for file transfers, so --progress has no
              effect,  the  "bytes sent", "bytes received", "literal data", and
              "matched data" statistics are too small, and the "speedup"  value
              is equivalent to a run where no file transfers were needed.

       --whole-file, -W
              This  option  disables  rsync's delta-transfer algorithm, causing
              the whole of all transferred files to be sent.  The transfer  may
              be  faster  if this option is used when the bandwidth between the
              source and destination machines is higher than the  bandwidth  to
              disk (especially when the "disk" is actually a networked filesys-
              tem).   This  is the default when both the source and destination
              are specified as local paths, but only if no batch-writing option
              is in effect.

       --no-whole-file, --no-W
              Disable whole-file updating when it is enabled by default  for  a
              local  transfer.   This  usually  slows rsync down, but it can be
              useful if you are trying to minimize the writes to  the  destina-
              tion  file (if combined with --inplace) or for testing the check-
              sum-based update algorithm.

              See also the --whole-file option.

       --checksum-choice=STR, --cc=STR
              This option overrides the checksum algorithms.  If one  algorithm
              name is specified, it is used for both the transfer checksums and
              the  pre-transfer  checksums (note that the pre-transfer checksum
              is only performed if --checksum is specified).  If two comma-sep-
              arated names are supplied, the first name  affects  the  transfer
              checksums,  and  the  second name affects the pre-transfer check-
              sums.

              The checksum options that you may be able to use are:

              o      auto (the default automatic choice)

              o      xxh128

              o      xxh3

              o      xxh64 (aka xxhash)

              o      md5

              o      md4

              o      sha1

              o      none

              Run rsync --version to see the  default  checksum  list  compiled
              into your version (which may differ from the list above).

              If  "none"  is  specified  for  the  first  (or  only)  name, the
              --whole-file option is forced on and no checksum verification  is
              performed  on  the  transferred data.  If "none" is specified for
              the second (or only) name, the --checksum option cannot be used.

              The "auto" option is the default, where rsync bases its algorithm
              choice on a negotiation between the client and the server as fol-
              lows:

              When both sides of the transfer are at least 3.2.0 (released June
              2020), each side chooses its own  most-preferred  algorithm  that
              also  appears  in  the peer's list.  Both sides order their lists
              strongest-first, so they converge on the strongest mutual choice.
              If no common checksum choice is found, rsync exits with an error.
              If the remote rsync is too old to support checksum negotiation, a
              value is chosen based on the protocol version (which chooses  be-
              tween MD5 and various flavors of MD4 based on protocol age).

              The  default  order  can be customized by setting the environment
              variable RSYNC_CHECKSUM_LIST to a space-separated list of accept-
              able checksum names.  If the string contains a "&" character,  it
              is  separated into the "client string & server string", otherwise
              the same string applies to both.  If the string (or  string  por-
              tion) contains no non-whitespace characters, the default checksum
              list  is  used.   This  method  does not allow you to specify the
              transfer checksum separately from the pre-transfer checksum,  and
              it  discards  "auto" and all unknown checksum names.  A list with
              only invalid names results in a failed negotiation.

              The use of the --checksum-choice option overrides  this  environ-
              ment list.

       --one-file-system, -x
              This tells rsync to avoid crossing a filesystem boundary when re-
              cursing.  This does not limit the user's ability to specify items
              to copy from multiple filesystems, just rsync's recursion through
              the hierarchy of each directory that the user specified, and also
              the  analogous  recursion  on the receiving side during deletion.
              Also keep in mind that rsync treats a "bind" mount  to  the  same
              device as being on the same filesystem.

              If  this option is repeated, rsync omits all mount-point directo-
              ries from the copy.  Otherwise, it includes an empty directory at
              each mount-point it  encounters  (using  the  attributes  of  the
              mounted directory because those of the underlying mount-point di-
              rectory are inaccessible).

              If  rsync has been told to collapse symlinks (via --copy-links or
              --copy-unsafe-links), a symlink to a directory on another  device
              is  treated  like a mount-point.  Symlinks to non-directories are
              unaffected by this option.

       --ignore-non-existing, --existing
              This tells rsync to skip creating files  (including  directories)
              that do not exist yet on the destination.  If this option is com-
              bined with the --ignore-existing option, no files will be updated
              (which  can  be useful if all you want to do is delete extraneous
              files).

              This option is a TRANSFER RULE, so don't expect any exclude  side
              effects.

       --ignore-existing
              This tells rsync to skip updating files that already exist on the
              destination  (this does not ignore existing directories, or noth-
              ing would get done).  See also --ignore-non-existing.

              This option is a TRANSFER RULE, so don't expect any exclude  side
              effects.

              This  option  can  be  useful  for  those doing backups using the
              --link-dest option when they need to continue a backup  run  that
              got  interrupted.   Since  a --link-dest run is copied into a new
              directory hierarchy (when it  is  used  properly),  using  [--ig-
              nore-existing  will  ensure  that the already-handled files don't
              get tweaked (which avoids a change in permissions  on  the  hard-
              linked  files).   This does mean that this option is only looking
              at the existing files in the destination hierarchy itself.

              When --info=skip2 is used  rsync  will  output  "FILENAME  exists
              (INFO)"  messages  where the INFO indicates one of "type change",
              "sum change" (requires -c), "file change"  (based  on  the  quick
              check),  "attr change", or "uptodate".  Using --info=skip1 (which
              is also implied by 2 -v options) outputs the exists message with-
              out the INFO suffix.

       --remove-source-files
              This tells rsync to remove from the sending side the files (mean-
              ing non-directories) that are a part of  the  transfer  and  have
              been successfully duplicated on the receiving side.

              Note  that  you  should only use this option on source files that
              are quiescent.  If you are using this to move files that show  up
              in  a  particular  directory over to another host, make sure that
              the finished files get renamed into the source directory, not di-
              rectly written into it, so that rsync can't possibly  transfer  a
              file that is not yet fully written.  If you can't first write the
              files  into  a different directory, you should use a naming idiom
              that lets rsync avoid transferring files that are  not  yet  fin-
              ished (e.g. name the file "foo.new" when it is written, rename it
              to  "foo"  when  it  is  done,  and  then  use  the  option --ex-
              clude='*.new' for the rsync transfer).

              Rsync will skip the sender-side removal, and output an error,  if
              the file's size or modify time has not stayed unchanged.

              If  the copy is local, rsync will ensure that the sender does not
              remove a file the receiver just verified, such as when  the  user
              accidentally  makes the source and destination directory the same
              path.

       --delete
              This tells rsync to delete extraneous files  from  the  receiving
              side  (those  that don't exist on the sending side), but only for
              the directories that are being synchronized.  You must have asked
              rsync to send the whole directory (e.g. "dir" or "dir/"),  rather
              than asking for all the files in a directory via a wildcard (e.g.
              "dir/*"),  since  the wildcard is expanded by the shell and rsync
              thus gets a request to transfer individual files, not the  files'
              parent  directory.  Files that are excluded from the transfer are
              also excluded from being deleted unless you use the  --delete-ex-
              cluded  option  or mark the rules as only matching on the sending
              side (see the include/exclude modifiers in the FILTER RULES  sec-
              tion).

              This  option  has  no  effect unless either --recursive or --dirs
              (-d) is enabled.  In the latter case, deletions only occur in di-
              rectories whose contents are being copied.

              This option can be dangerous if used incorrectly! It  is  a  very
              good  idea  to first try a run using the --dry-run (-n) option to
              see what files are going to be deleted.

              If the sending side detects any I/O errors, then the deletion  of
              any  files  at  the  destination  will be automatically disabled.
              This is to prevent temporary filesystem failures (such as NFS er-
              rors) on the sending side from  causing  a  massive  deletion  of
              files  on  the destination.  You can override this with the --ig-
              nore-errors option.

              The --delete option may be combined with one of the --delete-WHEN
              options without conflict, as well as --delete-excluded.  However,
              if none of the --delete-WHEN options are  specified,  rsync  will
              choose  the --delete-during algorithm when talking to rsync 3.0.0
              (March 2008) or newer,  or  the  --delete-before  algorithm  when
              talking   to   an  older  rsync.   See  also  --delete-delay  and
              --delete-after.

       --delete-before
              Request that the file-deletions on the receiving side be done be-
              fore the transfer starts.  See --delete (which  is  implied)  for
              more details on file-deletion.

              Deleting  before  the  transfer  is  helpful if the filesystem is
              tight for space and removing extraneous files would help to  make
              the transfer possible.  However, it does introduce a delay before
              the  start of the transfer, and this delay might cause the trans-
              fer to timeout (if --timeout  was  specified).   It  also  forces
              rsync  to  use  the old, non-incremental recursion algorithm that
              requires rsync to scan all the files in the transfer into  memory
              at once (see --recursive).

       --delete-during, --del
              Request that the file-deletions on the receiving side be done in-
              crementally  as  the  transfer happens.  The per-directory delete
              scan is done right before each directory is checked for  updates,
              so  it  behaves  like a more efficient --delete-before, including
              doing the deletions prior to any per-directory filter files being
              updated.  See --delete (which is implied)  for  more  details  on
              file-deletion.

       --delete-delay
              Request that the file-deletions on the receiving side be computed
              during  the transfer (like --delete-during), and then removed af-
              ter the transfer completes.  This is useful  when  combined  with
              --delay-updates  and/or --fuzzy, and is more efficient than using
              --delete-after, but can behave differently, since  --delete-after
              computes  the  deletions in a separate pass after all updates are
              done.  If the number  of  removed  files  overflows  an  internal
              buffer, a temporary file will be created on the receiving side to
              hold the names (it is removed while open, so you shouldn't see it
              during  the  transfer).   If  the  creation of the temporary file
              fails, rsync will try to fall back to using --delete-after (which
              it cannot do if --recursive is doing an incremental  scan).   See
              --delete (which is implied) for more details on file-deletion.

       --delete-after
              Request that the file-deletions on the receiving side be done af-
              ter  the transfer has completed.  This is useful if you are send-
              ing new per-directory merge files as a part of the  transfer  and
              you  want their exclusions to take effect for the delete phase of
              the current transfer.  It also forces rsync to use the old,  non-
              incremental  recursion  algorithm that requires rsync to scan all
              the files in the transfer into memory at once (see  --recursive).
              See  --delete  (which  is implied) for more details on file-dele-
              tion.

              See also the --delete-delay option that might be a faster  choice
              for those that just want the deletions to occur at the end of the
              transfer.

       --delete-excluded
              This  option  turns  any  unqualified  exclude/include rules into
              server-side rules that do not affect the receiver's deletions.

              By default, an exclude or include has both a  server-side  effect
              (to "hide" and "show" files when building the server's file list)
              and  a  receiver-side  effect (to "protect" and "risk" files when
              deletions are occurring).  Any rule that has no modifier to spec-
              ify what sides it is executed on will be instead treated as if it
              were a server-side rule only, avoiding any "protect"  effects  of
              the rules.

              A rule can still apply to both sides even with this option speci-
              fied  if  the  rule  is given both the sender & receiver modifier
              letters (e.g., -f'-sr foo').   Receiver-side  protect/risk  rules
              can  also  be  explicitly specified to limit the deletions.  This
              saves you from having to edit a bunch  of  -f'- foo'  rules  into
              -f'-s foo'  (aka -f'H foo') rules (not to mention the correspond-
              ing includes).

              See the FILTER RULES section for more information.  See  --delete
              (which is implied) for more details on deletion.

       --ignore-missing-args
              When  rsync  is  first processing the explicitly requested source
              files (e.g.  command-line arguments or --files-from entries),  it
              is  normally  an  error if the file cannot be found.  This option
              suppresses that error, and does not try  to  transfer  the  file.
              This  does  not  affect subsequent vanished-file errors if a file
              was initially found to be present and later is no longer there.

       --delete-missing-args
              This option takes the behavior of  the  (implied)  --ignore-miss-
              ing-args option a step farther: each missing argument will become
              a  deletion  request of the corresponding destination file on the
              receiving side (should it exist).  If the destination file  is  a
              non-empty  directory,  it  will  only  be successfully deleted if
              --force or --delete are in effect.  Other than that, this  option
              is independent of any other type of delete processing.

              The missing source files are represented by special file-list en-
              tries which display as a "*missing" entry in the --list-only out-
              put.

       --ignore-errors
              Tells  --delete  to go ahead and delete files even when there are
              I/O errors.

       --force
              This option tells rsync to delete a non-empty directory  when  it
              is  to  be replaced by a non-directory.  This is only relevant if
              deletions are not active (see --delete for details).

       --max-delete=NUM
              This tells rsync not to delete more than NUM  files  or  directo-
              ries.   If  that  limit  is  exceeded,  all further deletions are
              skipped through the end of the transfer.  At the end, rsync  out-
              puts  a  warning (including a count of the skipped deletions) and
              exits with an error code of 25 (unless some more important  error
              condition also occurred).

              You  may specify --max-delete=0 to be warned about any extraneous
              files in the destination without removing any of them.   CAUTION:
              a   client   rsync   older   than   3.0.0   (March  2008)  treats
              --max-delete=0 as unlimited, so use --max-delete=-1 if  the  com-
              mand might be run by such an old rsync.  (A 3.0.0 or newer client
              protects   an   older   remote   by   forwarding  the  option  as
              --max-delete=-1.)

       --max-size=SIZE
              This tells rsync to avoid transferring any file  that  is  larger
              than  the specified SIZE.  A numeric value can be suffixed with a
              string to indicate the numeric units or left unqualified to spec-
              ify bytes, and the numeric value can have a fractional part, such
              as --max-size=1.5m.

              This option is a TRANSFER RULE, so don't expect any exclude  side
              effects.

              The  first letter of a units string can be B (bytes), K (kilo), M
              (mega), G (giga), T (tera), or P (peta).  If the string is a sin-
              gle char or has "ib" added to it (e.g. "G"  or  "GiB")  then  the
              units are multiples of 1024.  If you use a two-letter suffix that
              ends with a "B" (e.g. "kb") then you get units that are multiples
              of 1000.  The string's letters can be any mix of upper and lower-
              case that you want to use.

              Finally,  if the string ends with either "+1" or "-1", it is off-
              set by one byte in the indicated direction.  The largest possible
              value is usually 8192P-1.

              Examples:    --max-size=1.5mb-1    is    1499999    bytes,    and
              --max-size=2g+1 is 2147483649 bytes.

       --min-size=SIZE
              This  tells  rsync to avoid transferring any file that is smaller
              than the specified SIZE,  which  can  help  in  not  transferring
              small,  junk  files.  See the --max-size option for a description
              of SIZE and other info.

       --max-alloc=SIZE
              By default rsync limits an individual malloc/realloc to about 1GB
              in size.  For most people this limit works just fine and prevents
              a protocol error causing rsync to request massive amounts of mem-
              ory.  However, if you have many millions of files in a  transfer,
              a  large  amount of server memory, and you don't want to split up
              your transfer into multiple parts, you can increase the per-allo-
              cation limit to something larger, allowing rsync to consume  more
              memory.

              Keep  in mind that this is not a limit on the total size of allo-
              cated memory.  It is a sanity-check value for each individual al-
              location.

              See the --max-size option for a description of how  SIZE  can  be
              specified.  The default suffix if none is given is bytes.

              A  value of 0 is an easy way to say "the largest limit this build
              supports".  It resolves to the same ceiling an explicit  SIZE  is
              checked against, so it is never a higher limit than one you could
              have typed out yourself.

              Because the option is passed to the remote rsync as you wrote it,
              each side resolves a 0 against its own maximum.  That makes 0 the
              only spelling that is correct for both ends of a transfer between
              hosts of different word sizes: a literal value large enough to be
              useful  on  a  64-bit client is rejected as too large by a 32-bit
              daemon.

              A value of 0 was accepted beginning  in  3.2.3  and  rejected  in
              3.5.0; the release after 3.5.0 accepts it again.

              A  daemon  administrator  who does not want clients to change the
              configured allocation ceiling can set  refuse options = max-alloc
              in  the module's rsyncd.conf.  This refuses every client-supplied
              value, including 0.

              You can set  a  default  value  using  the  environment  variable
              RSYNC_MAX_ALLOC  using  the same SIZE values as supported by this
              option.  If the remote rsync doesn't understand  the  --max-alloc
              option,  you  can  override  an environmental value by specifying
              --max-alloc=1g, which will make rsync avoid sending the option to
              the remote side (because "1G" is the default).

       --block-size=SIZE, -B
              This forces the block size used in rsync's  delta-transfer  algo-
              rithm  to  a  fixed  value.  It is normally selected based on the
              size of each file being updated.  See the  technical  report  for
              details.

              The  SIZE  can  be  specified  with  a  suffix as detailed in the
              --max-size option.

       --rsh=COMMAND, -e
              This option allows you to choose an alternative remote shell pro-
              gram to use for communication between the local and remote copies
              of rsync.  Typically, rsync is configured to use ssh by default.

              If this option is used with  [user@]host::module/path,  then  the
              remote  shell  COMMAND will be used to run an rsync daemon on the
              remote host, and all data will be transmitted through that remote
              shell connection, rather than through a direct socket  connection
              to  a  running  rsync  daemon  on the remote host.  See the USING
              RSYNC-DAEMON  FEATURES  VIA  A  REMOTE-SHELL  CONNECTION  section
              above.

              The  RSYNC_PORT  environment  variable  will be set when a daemon
              connection is being made via a remote-shell  connection.   It  is
              set  to  0  if the default daemon port is being assumed, or it is
              set to the value of the rsync port that was specified via  either
              the  --port  option  or a non-empty port value in an rsync:// URL
              (for example rsync://host.example.com:984).  This  is  useful  if
              the  program being run is not actually rsync but rather something
              such as an SSL or stunnel  helper  script;  the  script  can  use
              RSYNC_PORT to determine whether it should connect to a default or
              alternate port.

              Command-line  arguments  are  permitted  in COMMAND provided that
              COMMAND is presented to rsync as a single argument.  You must use
              spaces (not tabs or other whitespace) to separate the command and
              arguments from each other, and you can use single- and/or double-
              quotes to preserve spaces in an argument (but  not  backslashes).
              Note  that  doubling a single-quote inside a single-quoted string
              gives you a single-quote; likewise for double-quotes (though  you
              need  to  pay attention to which quotes your shell is parsing and
              which quotes rsync is parsing).  Some examples:

                  -e 'ssh -p 2234'
                  -e 'ssh -o "ProxyCommand nohup ssh firewall nc -w1 %h %p"'

              (Note that ssh users can alternately customize site-specific con-
              nect options in their .ssh/config file.)

              You can also choose the remote shell program using the  RSYNC_RSH
              environment  variable,  which accepts the same range of values as
              -e.

              See also the --blocking-io option which is affected by  this  op-
              tion.

       --rsync-path=PROGRAM
              Use  this  to specify what program is to be run on the remote ma-
              chine to start-up rsync.  Often used when rsync is not in the de-
              fault    remote-shell's    path    (e.g.    --rsync-path=/usr/lo-
              cal/bin/rsync).   Note  that  PROGRAM  is  run with the help of a
              shell, so it can be any  program,  script,  or  command  sequence
              you'd care to run, so long as it does not corrupt the standard-in
              & standard-out that rsync is using to communicate.

              One tricky example is to set a different default directory on the
              remote machine for use with the --relative option.  For instance:

                  rsync -avR --rsync-path="cd /a/b && rsync" host:c/d /e/

       --remote-option=OPTION, -M
              This  option  is used for more advanced situations where you want
              certain effects to be limited to one side of the  transfer  only.
              For  instance, if you want to pass --log-file=FILE and --fake-su-
              per to the remote system, specify it like this:

                  rsync -av -M --log-file=foo -M--fake-super src/ dest/

              If you want to have an option affect only the  local  side  of  a
              transfer  when  it normally affects both sides, send its negation
              to the remote side.  Like this:

                  rsync -av -x -M--no-x src/ dest/

              Be cautious using this, as it is possible  to  toggle  an  option
              that will cause rsync to have a different idea about what data to
              expect  next  over  the  socket,  and that will make it fail in a
              cryptic fashion.

              Note that you should use a separate -M option for each remote op-
              tion you want to pass.  On older rsync versions, the presence  of
              any  spaces  in  the  remote-option argument could cause it to be
              split into separate remote arguments, but this requires  the  use
              of --old-args in a modern rsync.

              When  performing a local transfer, the "local" side is the sender
              and the "remote" side is the receiver.

              Note some versions of the popt option-parsing library have a  bug
              in them that prevents you from using an adjacent argument with an
              equal   in   it   next   to   a   short   option   letter   (e.g.
              -M--log-file=/tmp/foo).  If this  bug  affects  your  version  of
              popt,  you  can  use  the  version  of popt that is included with
              rsync.

       --cvs-exclude, -C
              This is a useful shorthand for excluding a broad range  of  files
              that you often don't want to transfer between systems.  It uses a
              similar  algorithm  to  CVS  to determine if a file should be ig-
              nored.

              The exclude list is initialized to exclude  the  following  items
              (these  initial  items are marked as perishable -- see the FILTER
              RULES section):

                  RCS SCCS CVS CVS.adm RCSLOG cvslog.*  tags  TAGS  .make.state
                  .nse_depinfo  *~  #*  .#*  ,* _$* *$ *.old *.bak *.BAK *.orig
                  *.rej .del-* *.a *.olb *.o *.obj *.so *.exe  *.Z  *.elc  *.ln
                  core .svn/ .git/ .hg/ .bzr/

              then,  files  listed  in a $HOME/.cvsignore are added to the list
              and any files listed in the CVSIGNORE environment  variable  (all
              cvsignore names are delimited by whitespace).

              Finally,  any file is ignored if it is in the same directory as a
              .cvsignore file and matches one of the patterns  listed  therein.
              Unlike  rsync's filter/exclude files, these patterns are split on
              whitespace.  See the cvs(1) manual for more information.

              If you're combining -C with your own --filter rules,  you  should
              note  that these CVS excludes are appended at the end of your own
              rules, regardless of where the -C was placed on the command-line.
              This makes them a lower priority than any rules you specified ex-
              plicitly.  If you want to control where these  CVS  excludes  get
              inserted into your filter rules, you should omit the -C as a com-
              mand-line  option and use a combination of --filter=:C and --fil-
              ter=-C (either on your command-line or by putting  the  ":C"  and
              "-C"  rules into a filter file with your other rules).  The first
              option turns on the per-directory  scanning  for  the  .cvsignore
              file.   The  second  option does a one-time import of the CVS ex-
              cludes mentioned above.

       --filter=RULE, -f
              This option allows you to add rules to selectively  exclude  cer-
              tain  files  from  the  list of files to be transferred.  This is
              most useful in combination with a recursive transfer.

              You may use as many --filter options on the command line  as  you
              like  to  build  up  the list of files to exclude.  If the filter
              contains whitespace, be sure to quote it so that the shell  gives
              the  rule  to  rsync as a single argument.  You can use an under-
              score instead of a space to separate a rule from its argument.

              See the FILTER RULES section for detailed information on this op-
              tion.

       -F     The -F option is a shorthand for adding  two  --filter  rules  to
              your  command.  The first time it is used is a shorthand for this
              rule:

                  --filter='dir-merge /.rsync-filter'

              This tells rsync to look for  per-directory  .rsync-filter  files
              that  have  been  sprinkled  through  the hierarchy and use their
              rules to filter the files in the transfer.  If -F is repeated, it
              is a shorthand for this rule:

                  --filter='exclude .rsync-filter'

              This filters out the  .rsync-filter  files  themselves  from  the
              transfer.

              See  the  FILTER  RULES  section  for detailed information on how
              these options work.

       --exclude=PATTERN
              This option is a simplified form  of  the  --filter  option  that
              specifies  an exclude rule and does not allow the full rule-pars-
              ing syntax of normal filter rules.  This is equivalent to  speci-
              fying -f'- PATTERN'.

              See the FILTER RULES section for detailed information on this op-
              tion.

       --exclude-from=FILE
              This  option is related to the --exclude option, but it specifies
              a FILE that contains exclude  patterns  (one  per  line).   Blank
              lines  in  the  file are ignored, as are whole-line comments that
              start with ';' or '#' (filename rules that contain those  charac-
              ters are unaffected).

              If  a  line begins with "- " (dash, space) or "+ " (plus, space),
              then the type of rule is being explicitly specified as an exclude
              or an include (respectively).  Any rules without  such  a  prefix
              are taken to be an exclude.

              If a line consists of just "!", then the current filter rules are
              cleared before adding any further rules.

              If FILE is '-', the list will be read from standard input.

       --include=PATTERN
              This  option  is  a  simplified  form of the --filter option that
              specifies an include rule and does not allow the full  rule-pars-
              ing  syntax of normal filter rules.  This is equivalent to speci-
              fying -f'+ PATTERN'.

              See the FILTER RULES section for detailed information on this op-
              tion.

       --include-from=FILE
              This option is related to the --include option, but it  specifies
              a  FILE  that  contains  include  patterns (one per line).  Blank
              lines in the file are ignored, as are  whole-line  comments  that
              start  with ';' or '#' (filename rules that contain those charac-
              ters are unaffected).

              If a line begins with "- " (dash, space) or "+ "  (plus,  space),
              then the type of rule is being explicitly specified as an exclude
              or  an  include  (respectively).  Any rules without such a prefix
              are taken to be an include.

              If a line consists of just "!", then the current filter rules are
              cleared before adding any further rules.

              If FILE is '-', the list will be read from standard input.

       --files-from=FILE
              Using this option tells rsync to read the exact list of files  to
              transfer  from  FILE (or standard input if FILE is '-').  It also
              tweaks the default behavior of rsync to  make  transferring  just
              the specified files and directories easier:

              o      The --relative (-R) option is implied, which preserves the
                     path  information  that  is specified for each item in the
                     file (use --no-relative or --no-R if you want to turn that
                     off).

              o      The --dirs (-d) option is implied, which will  create  di-
                     rectories  specified in the list on the destination rather
                     than noisily skipping them (use --no-dirs or --no-d if you
                     want to turn that off).

              o      The --archive (-a) option's behavior does not imply  --re-
                     cursive (-r), so specify it explicitly, if you want it.

              o      These  side-effects  change the default state of rsync, so
                     the position of the --files-from option  on  the  command-
                     line  has no bearing on how other options are parsed (e.g.
                     -a works the same before or after  --files-from,  as  does
                     --no-R and all other options).

              The filenames that are read from the FILE are all relative to the
              source  directory:  any leading slash is removed, and ".." compo-
              nents are resolved away so an entry cannot rise above the  source
              directory --  e.g.  "../foo"  is taken as "foo" within the source
              directory.  An entry that still contains  an  active  ".."  after
              that  resolution  (one that cannot be collapsed) is rejected with
              an error.  Blank entries are ignored, as are whole-entry comments
              that start with ';' or '#'.  For example, take this command:

                  rsync -a --files-from=/tmp/foo /usr remote:/backup

              If /tmp/foo contains the  string  "bin"  (or  even  "/bin"),  the
              /usr/bin  directory  will be created as /backup/bin on the remote
              host.  If it contains "bin/" (note the trailing slash), the imme-
              diate contents of the directory would also be sent, without need-
              ing to be explicitly mentioned in the file.  In  both  cases,  if
              the  -r  option  was  enabled,  that directory's entire hierarchy
              would also be transferred (keep in mind that -r needs to be spec-
              ified explicitly with --files-from, since it is  not  implied  by
              -a.  Also note that the effect of the (enabled by default) -r op-
              tion  is  to  duplicate  only the path info that is read from the
              file -- it does not force the duplication of the source-spec path
              (/usr in this case).

              In addition, the --files-from file can be read  from  the  remote
              host  instead of the local host if you specify a "host:" in front
              of the file (the host must match one end of the transfer).  As  a
              short-cut,  you can specify just a prefix of ":" to mean "use the
              remote end of the transfer".  For example:

                  rsync -a --files-from=:/path/file-list src:/ /tmp/copy

              This would copy all the files specified  in  the  /path/file-list
              file that was located on the remote "src" host.

              If  the --iconv and --secluded-args options are specified and the
              --files-from filenames are being sent from one host  to  another,
              the  filenames will be translated from the sending host's charset
              to the receiving host's charset.

              NOTE: sorting the list of files in the --files-from  input  helps
              rsync to be more efficient, as it will avoid re-visiting the path
              elements  that are shared between adjacent entries.  If the input
              is not sorted, some path elements (implied directories)  may  end
              up  being scanned multiple times, and rsync will eventually undu-
              plicate them after they get turned into file-list elements.

       --from0, -0
              This tells rsync that the rules or filenames it reads from a file
              are terminated by a null ('\0')  character,  not  a  NL,  CR,  or
              CR+LF.      This    affects    --exclude-from,    --include-from,
              --files-from, and any merged files specified in a --filter  rule.
              It  does  not  affect  --cvs-exclude (since all names read from a
              .cvsignore file are split on whitespace).

       --old-args
              This option tells rsync not to protect the argument  values  sent
              to the remote side from unintended word-splitting or other misin-
              terpretation.   It also allows the client to treat an empty argu-
              ment as a "." instead of generating an error.

              The default in a modern rsync is  for  "shell-active"  characters
              (including  spaces) to be backslash-escaped in the arguments that
              are sent to the remote shell.  The wildcard characters *, ?, [, &
              ] are not escaped in filename arguments (allowing them to  expand
              into  multiple  filenames)  while being protected in option argu-
              ments, such as --usermap.

              If you have a script that wants to use old-style argument  split-
              ting  in  its filenames, specify this option once.  If the remote
              shell has a problem with any backslash escapes  at  all,  specify
              this option twice.

              You may also control this setting via the RSYNC_OLD_ARGS environ-
              ment  variable.  If it has the value "1", rsync will default to a
              single-option setting.  If it has the value "2" (or more),  rsync
              will  default to a repeated-option setting.  If it is "0", you'll
              get the default escaping behavior.   The  environment  is  always
              overridden  by  manually  specified  positive or negative options
              (the negative is --no-old-args).

              Note that this option also disables the extra safety  check  that
              ensures  that  a  remote  sender  isn't including extra top-level
              items in the file-list that you didn't request.  This side-effect
              is necessary because we can't know for sure what names to  expect
              when the remote shell is interpreting the arguments.

              This option conflicts with the --secluded-args option.

       --secluded-args, -s
              This  option  sends  all filenames and most options to the remote
              rsync via the protocol (rather than via the remote shell  command
              line), which avoids the possibility of the remote shell modifying
              them.  Wildcards are expanded on the remote host by rsync instead
              of a shell.

              Without  this  option, rsync does backslash-escaping of arguments
              to prevent things like space splitting and unwanted special-char-
              acter side-effects, which is normally  sufficient  to  avoid  un-
              wanted  modifications  by  the  shell.  This option is useful for
              those times that you need the argument's character set to be con-
              verted for the remote host, if the remote shell  is  incompatible
              with  the  default  backslash-escaping  method,  or there is some
              other reason that you want the majority of the options and  argu-
              ments to bypass the command-line of the remote shell.

              This  option  is incompatible with remote rsync versions prior to
              3.0.0 (March 2008).  It also has the drawback of being refused by
              restricted shells that want to be able to inspect all the  option
              values for safety.

              If you combine this option with --iconv, the arguments related to
              the  remote  side will be translated from the local to the remote
              character-set.  The translation happens before wild-cards are ex-
              panded.  See also the --files-from option.

              You may also control this setting via the RSYNC_PROTECT_ARGS  en-
              vironment  variable.   If  it  has a non-zero value, this setting
              will be enabled by default, otherwise it will be disabled by  de-
              fault.   Either state is overridden by a manually specified posi-
              tive or negative version of this option  (note  that  --no-s  and
              --no-secluded-args  are the negative versions).  This environment
              variable is also superseded by a non-zero RSYNC_OLD_ARGS environ-
              ment variable.

              This option conflicts with the --old-args option.

              This option used to be called --protect-args (before 3.2.6,  Sep-
              tember 2022) and that older name can still be used (though speci-
              fying it as -s is always the easiest and most compatible choice).

       --trust-sender
              This  option  disables  two  extra validation checks that a local
              client performs on the file list generated by  a  remote  sender.
              This  option  should  only be used if you trust the sender to not
              put something malicious in the file list  (something  that  could
              possibly  be done via a modified rsync, a modified shell, or some
              other similar manipulation).

              Normally, the rsync client runs two extra validation checks  when
              pulling files from a remote rsync:

              o      It  verifies  that  additional  argument  items didn't get
                     added at the top of the transfer.

              o      It verifies that none of the items in the  file  list  are
                     names that should have been excluded (if filter rules were
                     specified).

              Note  that  various  options  can  turn  off one or both of these
              checks if the option interferes with  the  validation.   For  in-
              stance:

              o      Using  a per-directory filter file reads filter rules that
                     only the server knows about, so  the  filter  checking  is
                     disabled.

              o      Using  the  --old-args option allows the sender to manipu-
                     late the requested arguments, so the argument checking  is
                     disabled.

              o      Reading  the  files-from  list  from the server side means
                     that the client doesn't know the argument list, so the ar-
                     gument checking is disabled.

              o      Using --read-batch disables both checks  since  the  batch
                     file's  contents  will have been verified when it was cre-
                     ated.

              This option may help an under-powered client server if the  extra
              pattern  matching  is slowing things down on a huge transfer.  It
              could also be used for a transfer from  a  trusted  sender  as  a
              workaround  if  there  appeared  to  be a bug in the verification
              logic.

              When using this option it is a good idea to specify  a  dedicated
              destination directory, as discussed in the SECURITY section.

       --copy-as=USER[:GROUP]
              This option instructs rsync to use the USER and (if specified af-
              ter  a colon) the GROUP for the copy operations.  This only works
              if the user that is running  rsync  has  the  ability  to  change
              users.   If  the  group  is not specified then the user's default
              groups are used.

              This option can help to reduce the risk in the case  where  rsync
              is  being  run  as  root, copying into or out of a directory that
              might have live changes happening to it, and  you  want  to  make
              sure  that  root-level  read or write actions of system files are
              not possible.  While you could alternatively run all of rsync  as
              the specified user, sometimes you need the root-level host-access
              credentials to be used, so this allows rsync to drop root for the
              copying  part  of  the operation after the remote-shell or daemon
              connection is established.

              The option only affects one  side  of  the  transfer  unless  the
              transfer  is local, in which case it affects both sides.  Use the
              --remote-option   to   affect   the   remote   side,   such    as
              -M--copy-as=joe.   For a local transfer, the lsh (or lsh.sh) sup-
              port file provides a local-shell helper script that can  be  used
              to  allow a "localhost:" or "lh:" host-spec to be specified with-
              out needing to setup any remote shells, allowing you  to  specify
              remote options that affect the side of the transfer that is using
              the  host-spec  (and using hostname "lh" avoids the overriding of
              the remote directory to the user's home directory).

              For example, the following rsync writes the local files  as  user
              "joe":

                  sudo rsync -aiv --copy-as=joe host1:backups/joe/ /home/joe/

              This  makes  all  files owned by user "joe", limits the groups to
              those that are available to that user, and  makes  it  impossible
              for  the  joe  user to do a timed exploit of the path to induce a
              change to a file that the joe user has no permissions to change.

              The following command does a local copy into the  "dest/"  direc-
              tory  as user "joe" (assuming you've installed support/lsh into a
              directory on your $PATH):

                  sudo rsync -aive lsh -M--copy-as=joe src/ lh:dest/

       --temp-dir=DIR, -T
              This option instructs rsync to use DIR  as  a  scratch  directory
              when  creating  temporary  copies of the files transferred on the
              receiving side.  The default behavior is to create each temporary
              file in the same directory as the  associated  destination  file.
              The temp-file names inside the specified DIR will not be prefixed
              with  an  extra  dot, though they will still have a random suffix
              added.

              This option is most often used when the receiving disk  partition
              does  not  have  enough  free space to hold a copy of the largest
              file in the transfer.  In this case (i.e. when the scratch direc-
              tory is on a different disk partition), rsync will not be able to
              rename each received temporary file over the top of  the  associ-
              ated  destination  file,  but  instead  must  copy it into place.
              Rsync does this by copying the file over the top of the  destina-
              tion  file,  which  means  that the destination file will contain
              truncated data during this copy.  If this were not done this way,
              it would be possible for the old file to continue taking up  disk
              space  (if  someone  had  it  open),  and thus there might not be
              enough room to fit the new version on the disk at the same time.

              If you are using this option for reasons other than a shortage of
              disk space, you may wish to combine it with  the  --delay-updates
              option, which will ensure that all copied files get put into sub-
              directories in the destination hierarchy, awaiting the end of the
              transfer.  If you don't have enough room to duplicate all the ar-
              riving  files  on  the destination partition, another way to tell
              rsync that you aren't overly concerned about disk space is to use
              the --partial-dir option with a relative path; because this tells
              rsync that it is OK to stash off a copy of a  single  file  in  a
              subdirectory  in  the  destination  hierarchy, rsync will use the
              partial-dir as a staging area to bring over the copied file,  and
              then rename it into place from there. (Specifying a --partial-dir
              with an absolute path does not have this side-effect.)

       --fuzzy, -y
              This  option tells rsync that it should look for a basis file for
              any destination file that is missing.  With  this  option,  rsync
              looks  in the same directory as the destination file for either a
              file that has an identical size and  modified-time,  or  a  simi-
              larly-named  file.   If found, rsync uses the fuzzy basis file to
              try to speed up the transfer.

              If the option is repeated, the fuzzy scan will also  be  done  in
              any matching alternate destination directories that are specified
              via --compare-dest, --copy-dest, or --link-dest.

              Note that the use of the --delete option might get rid of any po-
              tential  fuzzy-match files, so either use --delete-after or spec-
              ify some filename exclusions if you need to prevent this.

       --compare-dest=DIR
              This option instructs rsync to use DIR on the destination machine
              as an additional hierarchy to compare destination  files  against
              doing  transfers (if the files are missing in the destination di-
              rectory).  If a file is found in DIR that  is  identical  to  the
              sender's  file,  the file will NOT be transferred to the destina-
              tion directory.  This is useful for creating a sparse  backup  of
              just files that have changed from an earlier backup.  This option
              is typically used to copy into an empty (or newly created) direc-
              tory.

              Multiple  --compare-dest  directories may be provided, which will
              cause rsync to search the list in the order specified for an  ex-
              act  match.  If a match is found that differs only in attributes,
              a local copy is made and the attributes updated.  If a  match  is
              not  found, a basis file from one of the DIRs will be selected to
              try to speed up the transfer.

              If DIR is a relative path, it is relative to the destination  di-
              rectory.  See also --copy-dest and --link-dest.

              NOTE: rsync will remove a file from a non-empty destination hier-
              archy if an exact match is found in one of the compare-dest hier-
              archies, making the end result more closely match a fresh copy.

       --copy-dest=DIR
              This option behaves like --compare-dest, but rsync will also copy
              unchanged files found in DIR to the destination directory using a
              local copy.  This is useful for doing transfers to a new destina-
              tion while leaving existing files intact, and then doing a flash-
              cutover when all files have been successfully transferred.

              Multiple  --copy-dest  directories  may  be  provided, which will
              cause rsync to search the list in the order specified for an  un-
              changed  file.  If a match is not found, a basis file from one of
              the DIRs will be selected to try to speed up the transfer.

              If DIR is a relative path, it is relative to the destination  di-
              rectory.  See also --compare-dest and --link-dest.

       --link-dest=DIR
              This  option  behaves  like  --copy-dest, but unchanged files are
              hard linked from DIR to the  destination  directory.   The  files
              must  be identical in all preserved attributes (e.g. permissions,
              possibly ownership) in order for the files to be linked together.
              An example:

                  rsync -av --link-dest=$PWD/prior_dir host:src_dir/ new_dir/

              If files aren't linking,  double-check  their  attributes.   Also
              check  if  some  attributes are getting forced outside of rsync's
              control, such a mount option that squishes root to a single user,
              or mounts a removable drive with generic ownership  (such  as  OS
              X's "Ignore ownership on this volume" option).

              Multiple  --link-dest  directories  may  be  provided, which will
              cause rsync to search the list in the order specified for an  ex-
              act  match (there is a limit of 20 such directories).  If a match
              is found that differs only in attributes, a local  copy  is  made
              and  the  attributes  updated.   If a match is not found, a basis
              file from one of the DIRs will be selected to try to speed up the
              transfer.

              Not every filesystem can hard-link a symlink, a  device  node,  a
              FIFO or a socket, and the destination need not agree with the one
              rsync  was  built  on -- macOS builds on APFS, which can, and may
              write to HFS+, which cannot.  Where the  destination  refuses  to
              link such an entry, it is copied instead and the transfer carries
              on,  so  only that entry loses the space saving.  This applies to
              any refusal, because the  error  alone  does  not  identify  one:
              link(2)  reports  EPERM  both for a filesystem without hard links
              and for an ordinary permission refusal.  Regular files  have  al-
              ways behaved this way.

              One case is not covered.  With --hard-links (-H), a group of such
              entries  hard-linked  to  each other in the source needs a second
              link, from the first member to the rest, inside  the  destination
              itself.   Where  that  link  is refused too -- a destination that
              cannot hard-link the type at all -- the members after  the  first
              are not created and the transfer fails.  A --link-dest on another
              filesystem is fine: only the link to DIR is impossible there, and
              the ones within the destination still succeed.

              This option works best when copying into an empty destination hi-
              erarchy,  as existing files may get their attributes tweaked, and
              that can  affect  alternate  destination  files  via  hard-links.
              Also,  itemizing  of  changes  can  get a bit muddled.  Note that
              prior to version 3.1.0 (September 2013),  an  alternate-directory
              exact  match  would  never be found (nor linked into the destina-
              tion) when a destination file already exists.

              Note that if you combine this option with  --ignore-times,  rsync
              will  not link any files together because it only links identical
              files together as a substitute for transferring the  file,  never
              as an additional check after the file is updated.

              If  DIR is a relative path, it is relative to the destination di-
              rectory.  See also --compare-dest and --copy-dest.

              Note that rsync versions prior to 2.6.1 (April 2004)  had  a  bug
              that  could  prevent --link-dest from working properly for a non-
              super-user when --owner (-o) was specified (or implied).  You can
              work-around this bug by avoiding the -o option (or using  --no-o)
              when sending to a really old remote rsync.

       --compress, -z
              With this option, rsync compresses the file data as it is sent to
              the  destination  machine, which reduces the amount of data being
              transmitted -- something that is useful over a slow connection.

              Rsync supports multiple compression methods and will  choose  one
              for  you  unless you force the choice using the --compress-choice
              (--zc) option.

              Run rsync --version to see the  default  compress  list  compiled
              into your version.

              When  both  sides of the transfer are at least 3.2.0 (June 2020),
              each side chooses its own most-preferred algorithm that also  ap-
              pears   in  the  peer's  list.   Both  sides  order  their  lists
              strongest-first, so they converge on the strongest mutual choice.
              If no common compress choice is found, rsync exits with an error.
              If the remote rsync is too old to support  checksum  negotiation,
              its list is assumed to be "zlib".

              The  default  order  can be customized by setting the environment
              variable RSYNC_COMPRESS_LIST to a space-separated list of accept-
              able compression names.  If the string contains a "&"  character,
              it  is separated into the "client string & server string", other-
              wise the same string applies to both.  If the string  (or  string
              portion)  contains no non-whitespace characters, the default com-
              press list is used.  Any unknown compression names are  discarded
              from  the  list,  but a list with only invalid names results in a
              failed negotiation.

              There are some older rsync versions that were configured  to  re-
              ject  a  -z  option and require the use of -zz because their com-
              pression library was not compatible with the  default  zlib  com-
              pression  method.   You  can usually ignore this weirdness unless
              the rsync server complains and tells you to specify -zz.

       --compress-choice=STR, --zc=STR
              This option can be used to override the automatic negotiation  of
              the  compression  algorithm  that occurs when --compress is used.
              The option implies --compress unless "none" was specified,  which
              instead implies --no-compress.

              The compression options that you may be able to use are:

              o      zstd

              o      lz4

              o      zlibx

              o      zlib

              o      none

              Run  rsync --version  to  see  the default compress list compiled
              into your version (which may differ from the list above).

              Note that if you see an error about an  option  named  --old-com-
              press  or --new-compress, this is rsync trying to send the --com-
              press-choice=zlib or --compress-choice=zlibx option  in  a  back-
              ward-compatible manner that more rsync versions understand.  This
              error  indicates  that the older rsync version on the server will
              not allow you to force the compression type.

              Note that the "zlibx" compression algorithm is  just  the  "zlib"
              algorithm  with matched data excluded from the compression stream
              (to try to make it more compatible with an external  zlib  imple-
              mentation).

       --compress-level=NUM, --zl=NUM
              Explicitly  set the compression level to use (see --compress, -z)
              instead of using the default.  The --compress option  is  implied
              as  long  as the level chosen is not a "don't compress" level for
              the compression algorithm that is in effect (e.g.  zlib  compres-
              sion treats level 0 as "off").

              The  level  values vary depending on the checksum in effect.  Be-
              cause rsync will negotiate a checksum choice by default (when the
              remote rsync is new enough), it can be good to combine  this  op-
              tion with a --compress-choice (--zc) option unless you're sure of
              the choice in effect.  For example:

                  rsync -aiv --zc=zstd --zl=22 host:src/ dest/

              For  zlib  &  zlibx  compression the valid values are from 1 to 9
              with 6 being the default.  Specifying  --zl=0  turns  compression
              off, and specifying --zl=-1 chooses the default level of 6.

              For zstd compression the valid values are from -131072 to 22 with
              3 being the default. Specifying 0 chooses the default of 3.

              For  lz4  compression there are no levels, so the value is always
              0.

              If you specify a too-large or  too-small  value,  the  number  is
              silently  limited  to  a valid value.  This allows you to specify
              something like --zl=999999999 and be assured that you'll  end  up
              with  the  maximum compression level no matter what algorithm was
              chosen.

              If you want to know the compression  level  that  is  in  effect,
              specify  --debug=nstr  to  see  the  "negotiated string" results.
              This will report something like "Client compress: zstd (level 3)"
              (along with the checksum choice in effect).

       --compress-threads=NUM, --zt=NUM
              Set the number of threads to spawn when compressing data. Setting
              this option to 1 or more will instruct the compression library to
              spawn 1 or more threads for compression. Ideally, increasing  the
              number of threads will increase transfer speed if the transfer is
              CPU bound on the sender.

              This option does not affect decompression.

              Compression algorithms that allow threading:

              o      zstd  (only  when  libzstd is compiled with threading sup-
                     port)

              This option is ignored if one of the above alogithms is  not  se-
              lected as the --compression-choice or if compression not enabled.

       --skip-compress=LIST
              NOTE:  no compression method currently supports per-file compres-
              sion changes, so this option has no effect.

              Override the list of file suffixes that  will  be  compressed  as
              little  as  possible.   Rsync  can set the compression level on a
              per-file basis based on the file's suffix.   If  the  compression
              algorithm  has  an  "off"  level,  then no compression occurs for
              those files.  Other algorithms that support changing the  stream-
              ing level on-the-fly will have the level minimized to reduces the
              CPU usage as much as possible for a matching file.

              The  LIST  should  be one or more file suffixes (without the dot)
              separated by slashes (/).  You may specify an empty string to in-
              dicate that no files should be skipped.

              Simple character-class matching is supported: each  must  consist
              of  a list of letters inside the square brackets (e.g. no special
              classes, such as "[:alpha:]", are supported, and '-' has no  spe-
              cial meaning).

              The characters asterisk (*) and question-mark (?) have no special
              meaning.

              Here's  an  example that specifies 6 suffixes to skip (since 1 of
              the 5 rules matches 2 suffixes):

                  --skip-compress=gz/jpg/mp[34]/7z/bz2

              The default file suffixes in the skip-compress list in this  ver-
              sion of rsync are:

                  3g2  3gp  7z aac ace apk avi bz2 deb dmg ear f4v flac flv gpg
                  gz iso jar jpeg jpg lrz lz lz4 lzma lzo m1a m1v m2a m2ts  m2v
                  m4a  m4b m4p m4r m4v mka mkv mov mp1 mp2 mp3 mp4 mpa mpeg mpg
                  mpv mts odb odf odg odi odm odp ods odt oga ogg ogm  ogv  ogx
                  opus  otg  oth  otp  ots  ott  oxt png qt rar rpm rz rzip spx
                  squashfs sxc sxd sxg sxm sxw sz tbz tbz2 tgz tlz ts  txz  tzo
                  vob war webm webp xz z zip zst

              This  list  will  be replaced by your --skip-compress list in all
              but one situation: a copy from  a  daemon  rsync  will  add  your
              skipped  suffixes  to  its list of non-compressing files (and its
              list may be configured to a different default).

       --numeric-ids
              With this option rsync will transfer numeric group and  user  IDs
              rather  than  using user and group names and mapping them at both
              ends.

              By default rsync will use the username and groupname to determine
              what ownership to give files.  The special uid 0 and the  special
              group  0  are never mapped via user/group names even if the --nu-
              meric-ids option is not specified.

              If a user or group has no name on the source system or it has  no
              match  on  the  destination  system, then the numeric ID from the
              source system is used instead.  See also the  use chroot  setting
              in  the  rsyncd.conf  manpage for some comments on how the chroot
              setting affects rsync's ability to look up the names of the users
              and groups and what you can do about it.

       --usermap=STRING, --groupmap=STRING
              These options allow you to specify users and groups  that  should
              be  mapped  to other values by the receiving side.  The STRING is
              one or more FROM:TO pairs of values  separated  by  commas.   Any
              matching  FROM  value from the sender is replaced with a TO value
              from the receiver.  You may specify usernames or user IDs for the
              FROM and TO values, and the FROM value may also  be  a  wild-card
              string,  which  will be matched against the sender's names (wild-
              cards do NOT match against ID numbers, though see below for why a
              '*' matches everything).  You may instead specify a range  of  ID
              numbers via an inclusive range: LOW-HIGH.  For example:

                  --usermap=0-99:nobody,wayne:admin,*:normal --groupmap=usr:1,1:usr

              The  first match in the list is the one that is used.  You should
              specify all your user mappings using a single  --usermap  option,
              and/or all your group mappings using a single --groupmap option.

              Note  that  the  sender's  name  for the 0 user and group are not
              transmitted to the receiver, so you  should  either  match  these
              values  using  a  0,  or use the names in effect on the receiving
              side (typically "root").  All other FROM names match those in use
              on the sending side.  All TO names match those in use on the  re-
              ceiving side.

              Any  IDs  that do not have a name on the sending side are treated
              as having an empty name for the purpose of matching.  This allows
              them to be matched via a "*" or using an  empty  name.   For  in-
              stance:

                  --usermap=:nobody --groupmap=*:nobody

              An  empty  FROM  value  matches only sender-side IDs that have no
              name.  It is not a wildcard for named users or  groups;  use  "*"
              when you want to map every sender-side name.

              When  the  --numeric-ids option is used, the sender does not send
              any names, so all the IDs are treated as having  an  empty  name.
              This  means  that you will need to specify numeric FROM values if
              you want to map these nameless IDs to different values.

              For the --usermap option to work, the receiver will  need  to  be
              running  as  a  super-user (see also the --super and --fake-super
              options).  For the --groupmap option to work, the  receiver  will
              need to have permissions to set that group.

              The  --usermap  option  implies  the --owner (-o) option, and the
              --groupmap option implies the --group (-g)  option  (since  rsync
              needs  to  have  those options enabled for the mapping options to
              work).

              An older rsync client may need to use -s  to  avoid  a  complaint
              about  wildcard characters, but a modern rsync handles this auto-
              matically.

       --chown=USER:GROUP
              This option forces all files to  be  owned  by  USER  with  group
              GROUP.   This  is  a  simpler  interface  than  using --usermap &
              --groupmap directly, but it is implemented  using  those  options
              internally,  thus  they  cannot  be mixed.  If either the USER or
              GROUP is empty, no mapping for the omitted user/group will occur.
              If GROUP is empty, the trailing colon may be omitted, but if USER
              is empty, a leading colon must be supplied.

              If you specify "--chown=foo:bar", this is  exactly  the  same  as
              specifying  "--usermap=*:foo --groupmap=*:bar",  only easier (and
              with the same implied --owner and/or --group options).

              An older rsync client may need to use -s  to  avoid  a  complaint
              about  wildcard characters, but a modern rsync handles this auto-
              matically.

       --timeout=SECONDS
              This option allows you to set a maximum I/O timeout  in  seconds.
              If  no data is transferred for the specified time then rsync will
              exit.  The default is 0, which means no timeout.

       --contimeout=SECONDS
              This option allows you to set the amount of time that rsync  will
              wait  for  its  connection to an rsync daemon to succeed.  If the
              timeout is reached, rsync exits with an error.

       --address=ADDRESS
              By default rsync will bind to the wildcard address when  connect-
              ing to an rsync daemon.  The --address option allows you to spec-
              ify a specific IP address (or hostname) to bind to.

              See also the daemon version of the --address option.

       --port=PORT
              This  specifies  an  alternate TCP port number to use rather than
              the default of 873.  This is only needed if  you  are  using  the
              double-colon  (::)  syntax to connect with an rsync daemon (since
              the URL syntax has a way to specify the port as  a  part  of  the
              URL).

              See also the daemon version of the --port option.

       --sockopts=OPTIONS
              This  option  can provide endless fun for people who like to tune
              their systems to the utmost degree.  You can  set  all  sorts  of
              socket  options  which  may  make  transfers faster (or slower!).
              Read the manpage for the setsockopt() system call for details  on
              some  of  the options you may be able to set.  By default no spe-
              cial socket options are set.  This  only  affects  direct  socket
              connections to a remote rsync daemon.

              See also the daemon version of the --sockopts option.

       --blocking-io
              This  tells  rsync  to  use  blocking I/O when launching a remote
              shell transport.  If the remote shell is  either  rsh  or  remsh,
              rsync  defaults  to  using blocking I/O, otherwise it defaults to
              using non-blocking I/O. (Note that ssh prefers non-blocking I/O.)

       --outbuf=MODE
              This sets the output buffering mode.  The mode can be  None  (aka
              Unbuffered),  Line, or Block (aka Full).  You may specify as lit-
              tle as a single letter for the mode, and use upper or lower case.

              The main use of this option is to change Full buffering  to  Line
              buffering when rsync's output is going to a file or pipe.

       --itemize-changes, -i
              Requests  a  simple  itemized  list of the changes that are being
              made to each file, including attribute changes.  This is  exactly
              the same as specifying --out-format='%i %n%L'.  If you repeat the
              option,  unchanged files will also be output, but only if the re-
              ceiving rsync is at least version 2.6.7 (March 2006). You can use
              -vv with older versions of rsync, but that also turns on the out-
              put of other verbose messages.

              The "%i" escape has a cryptic output that  is  11  letters  long.
              The general format is like the string YXcstpoguax, where Y is re-
              placed  by  the  type  of update being done, X is replaced by the
              file-type, and the other letters represent attributes that may be
              output if they are being modified.

              The update types that replace the Y are as follows:

              o      A < means that a file is being transferred to  the  remote
                     host (sent).

              o      A  >  means  that a file is being transferred to the local
                     host (received).

              o      A c means that a local change/creation  is  occurring  for
                     the  item  (such  as  the  creation  of a directory or the
                     changing of a symlink, etc.).

              o      A h means that the item is a hard  link  to  another  item
                     (requires --hard-links).

              o      A  .  means  that the item is not being updated (though it
                     might have attributes that are being modified).

              o      A * means that the rest of the itemized-output  area  con-
                     tains a message (e.g. "deleting").

              The  file-types  that  replace the X are: f for a file, a d for a
              directory, an L for a symlink, a D for a device, and a  S  for  a
              special file (e.g. named sockets and fifos).

              The  other  letters  in the string indicate if some attributes of
              the file have changed, as follows:

              o      "." - the attribute is unchanged.

              o      "+" - the file is newly created.

              o      " " - all the attributes are unchanged (all dots  turn  to
                     spaces).

              o      "?"  -  the  change  is  unknown (when the remote rsync is
                     old).

              o      A letter indicates an attribute is being updated.

              The attribute that is associated with each letter is as follows:

              o      A c means either that  a  regular  file  has  a  different
                     checksum  (requires --checksum) or that a symlink, device,
                     or special file has a changed value.  Note that if you are
                     sending files to an rsync prior  to  3.0.1  (April  2008),
                     this change flag will be present only for checksum-differ-
                     ing regular files.

              o      A s means the size of a regular file is different and will
                     be updated by the file transfer.

              o      A  t means the modification time is different and is being
                     updated to the sender's value (requires --times).  An  al-
                     ternate  value  of T means that the modification time will
                     be  set  to  the  transfer  time,  which  happens  when  a
                     file/symlink/device  is updated without --times and when a
                     symlink is changed and the receiver can't set its time.

              o      A p means the permissions are different and are being  up-
                     dated to the sender's value (requires --perms).

              o      An  o means the owner is different and is being updated to
                     the sender's value (requires --owner and super-user privi-
                     leges).

              o      A g means the group is different and is being  updated  to
                     the  sender's value (requires --group and the authority to
                     set the group).

              o

                     o      A u|n|b indicates the following information:

                            u  means the access (use) time is different and  is
                            being  updated  to  the  sender's  value  (requires
                            --atimes)

                     o      n means the create time (newness) is different  and
                            is  being  updated  to the sender's value (requires
                            --crtimes)

                     o      b means that both the access and create  times  are
                            being updated

              o      An a means that the ACL information is being changed.

              o      An  x means that the extended attribute information is be-
                     ing changed.

              One other output is possible: when deleting files, the "%i"  will
              output the string "*deleting" for each item that is being removed
              (assuming  that  you are talking to a recent enough rsync that it
              logs deletions instead of outputting them as a verbose message).

       --out-format=FORMAT
              This allows you to specify exactly what the rsync client  outputs
              to  the  user on a per-update basis.  The format is a text string
              containing embedded single-character  escape  sequences  prefixed
              with  a percent (%) character.  A default format of "%n%L" is as-
              sumed if either --info=name or -v is specified  (this  tells  you
              just  the  name  of the file and, if the item is a link, where it
              points).  For a full list of the possible escape characters,  see
              the log format setting in the rsyncd.conf manpage.

              Specifying  the  --out-format  option implies the --info=name op-
              tion, which will mention each file, directory, etc. that gets up-
              dated in a significant way (a transferred file, a recreated  sym-
              link/device,  or a touched directory).  In addition, if the item-
              ize-changes escape (%i) is included in the string  (e.g.  if  the
              --itemize-changes  option  was  used),  the  logging of names in-
              creases to mention any item that is changed in any way  (as  long
              as  the  receiving  side  is  at  least  2.6.4).  See the --item-
              ize-changes option for a description of the output of "%i".

              Rsync will output the out-format string prior to a file's  trans-
              fer unless one of the transfer-statistic escapes is requested, in
              which case the logging is done at the end of the file's transfer.
              When this late logging is in effect and --progress is also speci-
              fied,  rsync  will  also output the name of the file being trans-
              ferred prior to its progress information (followed, of course, by
              the out-format output).

       --log-file=FILE
              This option causes rsync to write the log of what it is doing  to
              a  file.   This is similar to the logging that a daemon does, but
              can be requested for the client side and/or the server side of  a
              non-daemon  transfer.   If specified as a client option, transfer
              logging will be enabled with a default format of "%i %n%L".   See
              the --log-file-format option if you wish to override this.

              Here's  an  example  command that requests the remote side to log
              what is happening:

                  rsync -av --remote-option=--log-file=/tmp/rlog src/ dest/

              This is very useful if you need to  debug  why  a  connection  is
              closing unexpectedly.

              See also the daemon version of the --log-file option.

       --log-file-format=FORMAT
              This allows you to specify exactly what per-update logging is put
              into the file specified by the --log-file option (which must also
              be specified for this option to have any effect).  If you specify
              an  empty  string, updated files will not be mentioned in the log
              file.  For a list of the  possible  escape  characters,  see  the
              log format setting in the rsyncd.conf manpage.

              The  default  FORMAT used if --log-file is specified and this op-
              tion is not is '%i %n%L'.

              See also the daemon version of the --log-file-format option.

       --stats
              This tells rsync to print a verbose set of statistics on the file
              transfer, allowing you to tell how effective rsync's delta-trans-
              fer algorithm is for your data.  This  option  is  equivalent  to
              --info=stats2   if   combined   with   0  or  1  -v  options,  or
              --info=stats3 if combined with 2 or more -v options.

              The current statistics are as follows:

              o      Number of files is  the  count  of  all  "files"  (in  the
                     generic sense), which includes directories, symlinks, etc.
                     The  total  count  will be followed by a list of counts by
                     filetype (if the total is non-zero).  For example:  "(reg:
                     5,  dir: 3, link: 2, dev: 1, special: 1)" lists the totals
                     for regular files,  directories,  symlinks,  devices,  and
                     special  files.  If any value is 0, it is completely omit-
                     ted from the list.

              o      Number of created files is the count of how  many  "files"
                     (generic sense) were created (as opposed to updated).  The
                     total  count will be followed by a list of counts by file-
                     type (if the total is non-zero).

              o      Number of deleted files is the count of how  many  "files"
                     (generic  sense)  were  deleted.   The total count will be
                     followed by a list of counts by filetype (if the total  is
                     non-zero).   Note  that  this line is only output if dele-
                     tions are in effect, and only if the  negotiated  protocol
                     is  at  least  31  (the default when both sides are 3.1.0,
                     September 2013, or newer).

              o      Number of regular files transferred is the count of normal
                     files that were updated via rsync's  delta-transfer  algo-
                     rithm, which does not include directories, symlinks, etc.

              o      Total file size  is the total sum of all file sizes in the
                     transfer.  This does not count any size for directories or
                     special files, but does include the size of symlinks.

              o      Total transferred file size is the total sum of all  files
                     sizes for just the transferred files.

              o      Literal data  is  how  much unmatched file-update data the
                     sender had to send to the receiver for it to recreate  the
                     updated files.

              o      Matched data  is  how  much  data the receiver got locally
                     when recreating the updated files.

              o      File list size is how big the file-list data was when  the
                     sender  sent it to the receiver.  This is smaller than the
                     in-memory size for the file list due to  some  compressing
                     of duplicated data when rsync sends the list.

              o      File list generation time  is  the  number of seconds that
                     the sender spent creating the file list.  This requires  a
                     modern rsync on the sending side for this to be present.

              o      File list transfer time  is the number of seconds that the
                     sender spent sending the file list to the receiver.

              o      Total bytes sent is the count of all the bytes that  rsync
                     sent from the client side to the server side.

              o      Total bytes received is the count of all non-message bytes
                     that  rsync  received  by  the client side from the server
                     side. "Non-message" bytes means that we  don't  count  the
                     bytes  for  a  verbose message that the server sent to us,
                     which makes the stats more consistent.

       --8-bit-output, -8
              This tells rsync to leave all high-bit  characters  unescaped  in
              the output (to standard output or standard error) instead of try-
              ing  to  test  them to see if they're valid in the current locale
              and escaping the invalid ones.  All control characters (but never
              tabs) are always escaped, regardless of this option's setting.

              The escape idiom that started in 2.6.7 (March 2006) is to  output
              a literal backslash (\) and a hash (#), followed by exactly 3 oc-
              tal  digits.   For example, a newline would output as "\#012".  A
              literal backslash that is in a filename is not escaped unless  it
              is followed by a hash and 3 digits (0-9).

       --human-readable, -h
              Output numbers in a more human-readable format.  There are 3 pos-
              sible levels:

              1.     output numbers with a separator between each set of 3 dig-
                     its (either a comma or a period, depending on if the deci-
                     mal point is represented by a period or a comma).

              2.     output  numbers  in units of 1000 (with a character suffix
                     for larger units -- see below).

              3.     output numbers in units of 1024.

              The default is human-readable level 1.  Each -h option  increases
              the  level  by  one.  You can take the level down to 0 (to output
              numbers as pure digits)  by  specifying  the  --no-human-readable
              (--no-h) option.

              The  unit  letters  that  are  appended  in levels 2 and 3 are: K
              (kilo), M (mega), G (giga), T (tera), or P (peta).  For  example,
              a  1234567-byte  file  would output as 1.23M in level-2 (assuming
              that a period is your local decimal point).

              Backward compatibility note: versions of  rsync  prior  to  3.1.0
              (September  2013) do not support human-readable level 1, and they
              default to level 0.  Thus, specifying one or two -h options  will
              behave  in a comparable manner in old and new versions as long as
              you didn't specify a --no-h option prior to one or  more  -h  op-
              tions.  See the --list-only option for one difference.

       --partial
              By  default,  rsync will delete any partially transferred file if
              the transfer is interrupted.  In some circumstances  it  is  more
              desirable  to keep partially transferred files.  Using the --par-
              tial option tells rsync to keep the  partial  file  which  should
              make a subsequent transfer of the rest of the file much faster.

       --partial-dir=DIR
              This  option  modifies the behavior of the --partial option while
              also implying that it be  enabled.   This  enhanced  partial-file
              method  puts  any  partially transferred files into the specified
              DIR instead of writing the partial file out  to  the  destination
              file.   On the next transfer, rsync will use a file found in this
              directory as data to speed up the resumption of the transfer  and
              then delete it after it has served its purpose.

              Note that if --whole-file is specified (or implied), any partial-
              dir  files  that  are found for a file that is being updated will
              simply be removed (since rsync is  sending  files  without  using
              rsync's delta-transfer algorithm).

              Rsync will create the DIR if it is missing, but just the last di-
              rectory -- not the whole path.  This makes it easy to use a rela-
              tive  path (such as "--partial-dir=.rsync-partial") to have rsync
              create the partial-directory in the destination file's  directory
              when it is needed, and then remove it again when the partial file
              is  deleted.  Note that this directory removal is only done for a
              relative pathname, as it is expected that an absolute path is  to
              a directory that is reserved for partial-dir work.

              If  the partial-dir value is not an absolute path, rsync will add
              an exclude rule at the end of all your existing  excludes.   This
              will  prevent the sending of any partial-dir files that may exist
              on the sending side, and will also prevent the untimely  deletion
              of  partial-dir  items  on  the  receiving side.  An example: the
              above --partial-dir option would add the equivalent of this "per-
              ishable"  exclude  at  the  end  of  any  other   filter   rules:
              -f '-p .rsync-partial/'

              If  you are supplying your own exclude rules, you may need to add
              your own exclude/hide/protect rule for the partial-dir because:

              1.     the auto-added rule may be ineffective at the end of  your
                     other rules, or

              2.     you may wish to override rsync's exclude choice.

              For  instance,  if  you want to make rsync clean-up any left-over
              partial-directories that may be lying around, you should  specify
              --delete-after  and add a "risk" filter rule, e.g.  -f 'R .rsync-
              partial/'. Avoid using --delete-before or --delete-during  unless
              you don't need rsync to use any of the left-over partial-dir data
              during the current run.

              IMPORTANT:  the  partial-dir  directory should not be writable by
              other users or it is a security risk!  E.g. AVOID "/tmp"!

              You can also set the partial-dir value the RSYNC_PARTIAL_DIR  en-
              vironment  variable.   Setting  this  in the environment does not
              force --partial to be enabled, but rather it affects  where  par-
              tial files go when --partial is specified.  For instance, instead
              of  using  --partial-dir=.rsync-tmp  along  with  --progress, you
              could set RSYNC_PARTIAL_DIR=.rsync-tmp in  your  environment  and
              then  use  the -P option to turn on the use of the .rsync-tmp dir
              for partial transfers.  The only times that the --partial  option
              does not look for this environment value are:

              1.     when  --inplace  was  specified (since --inplace conflicts
                     with --partial-dir), and

              2.     when --delay-updates was specified (see below).

              When a modern rsync resumes the transfer of a file  in  the  par-
              tial-dir,  that  partial  file is now updated in-place instead of
              creating yet another tmp-file copy (so it maxes out at dest + tmp
              instead of dest + partial + tmp).  This requires both ends of the
              transfer to be at least version 3.2.0 (June 2020).

              For the purposes of the daemon-config's "refuse options" setting,
              --partial-dir does not imply --partial.  This is so  that  a  re-
              fusal  of  the --partial option can be used to disallow the over-
              writing of destination files with a partial transfer, while still
              allowing the safer idiom provided by --partial-dir.

       --delay-updates
              This option puts the temporary file from each updated file into a
              holding directory until the end of the transfer,  at  which  time
              all  the  files are renamed into place in rapid succession.  This
              attempts to make the updating of the files  a  little  closer  to
              atomic.   By  default the files are placed into a directory named
              .~tmp~ in each file's destination directory, but if you've speci-
              fied the --partial-dir option, that directory will  be  used  in-
              stead.   See the comments in the --partial-dir section for a dis-
              cussion of how this .~tmp~ dir will be excluded from  the  trans-
              fer,  and what you can do if you want rsync to cleanup old .~tmp~
              directories that might be lying around.  Conflicts with --inplace
              and --append.

              This option implies --no-inc-recursive since it  needs  the  full
              file list in memory in order to be able to iterate over it at the
              end.

              This  option  uses more memory on the receiving side (one bit per
              file transferred) and also requires enough free disk space on the
              receiving side to hold an additional  copy  of  all  the  updated
              files.   Note  also  that  you should not use an absolute path to
              --partial-dir unless:

              1.     there is no chance of any of the  files  in  the  transfer
                     having  the same name (since all the updated files will be
                     put into a single directory if the path is absolute), and

              2.     there are no mount points in the hierarchy (since the  de-
                     layed  updates  will  fail  if  they can't be renamed into
                     place).

              See also the "atomic-rsync" python script in the "support" subdi-
              rectory for an update algorithm that is even closer to atomic (it
              uses --link-dest and a parallel hierarchy of files).

       --prune-empty-dirs, -m
              This option tells the receiving rsync to get rid of empty  direc-
              tories from the file-list, including nested directories that have
              no  non-directory children.  This is useful for avoiding the cre-
              ation of a bunch of useless directories when the sending rsync is
              recursively scanning  a  hierarchy  of  files  using  include/ex-
              clude/filter rules.

              This  option  can  still leave empty directories on the receiving
              side if you make use of TRANSFER_RULES.

              Because the file-list is actually being pruned, this option  also
              affects  what  directories  get  deleted when a delete is active.
              However, keep in mind that excluded  files  and  directories  can
              prevent  existing items from being deleted due to an exclude both
              hiding source files and protecting destination  files.   See  the
              perishable filter-rule option for how to avoid this.

              You can prevent the pruning of certain empty directories from the
              file-list by using a global "protect" filter.  For instance, this
              option would ensure that the directory "emptydir" was kept in the
              file-list:

                  --filter 'protect emptydir/'

              Here's an example that copies all .pdf files in a hierarchy, only
              creating  the  necessary destination directories to hold the .pdf
              files, and ensures that any superfluous files and directories  in
              the destination are removed (note the hide filter of non-directo-
              ries being used instead of an exclude):

                  rsync -avm --del --include='*.pdf' -f 'hide,! */' src/ dest

              If  you  didn't want to remove superfluous destination files, the
              more time-honored options of  --include='*/' --exclude='*'  would
              work fine in place of the hide-filter (if that is more natural to
              you).

       --progress
              This option tells rsync to print information showing the progress
              of  the  transfer.   This  gives a bored user something to watch.
              With  a  modern  rsync   this   is   the   same   as   specifying
              --info=flist2,name,progress,  but  any user-supplied settings for
              those      info      flags      takes      precedence       (e.g.
              --info=flist0 --progress).

              While rsync is transferring a regular file, it updates a progress
              line that looks like this:

                  782448  63%  110.64kB/s    0:00:04

              In  this  example, the receiver has reconstructed 782448 bytes or
              63% of the sender's file, which is being reconstructed at a  rate
              of 110.64 kilobytes per second, and the transfer will finish in 4
              seconds if the current rate is maintained until the end.

              These  statistics can be misleading if rsync's delta-transfer al-
              gorithm is in use.  For example, if the sender's file consists of
              the basis file followed by additional  data,  the  reported  rate
              will  probably  drop  dramatically  when the receiver gets to the
              literal data, and the transfer will probably take much longer  to
              finish  than  the  receiver  estimated  as  it  was finishing the
              matched part of the file.

              When the file transfer finishes, rsync replaces the progress line
              with a summary line that looks like this:

                  1,238,099 100%  146.38kB/s    0:00:08  (xfr#5, to-chk=169/396)

              In this example, the file was 1,238,099 bytes long in total,  the
              average  rate of transfer for the whole file was 146.38 kilobytes
              per second over the 8 seconds that it took to  complete,  it  was
              the  5th transfer of a regular file during the current rsync ses-
              sion, and there are 169 more files for the receiver to check  (to
              see if they are up-to-date or not) remaining out of the 396 total
              files in the file-list.

              In an incremental recursion scan, rsync won't know the total num-
              ber  of  files  in the file-list until it reaches the ends of the
              scan, but since it starts to transfer files during the  scan,  it
              will  display  a line with the text "ir-chk" (for incremental re-
              cursion check) instead of "to-chk" until the point that it  knows
              the full size of the list, at which point it will switch to using
              "to-chk".   Thus,  seeing  "ir-chk"  lets you know that the total
              count of files in the file list is still going to  increase  (and
              each time it does, the count of files left to check will increase
              by the number of the files added to the list).

       -P     The  -P option is equivalent to "--partial --progress".  Its pur-
              pose is to make it much easier to specify these two options for a
              long transfer that may be interrupted.

              There is also a --info=progress2 option that  outputs  statistics
              based  on  the whole transfer, rather than individual files.  Use
              this flag without outputting a filename (e.g. avoid -v or specify
              --info=name0) if you want to see how the transfer is doing  with-
              out  scrolling the screen with a lot of names. (You don't need to
              specify the --progress option in order to use --info=progress2.)

              Finally, you can get an instant progress report by sending  rsync
              a  signal of either SIGINFO or SIGVTALRM.  On BSD systems, a SIG-
              INFO is generated by typing a  Ctrl+T  (Linux  doesn't  currently
              support a SIGINFO signal).  When the client-side process receives
              one  of those signals, it sets a flag to output a single progress
              report which is output when the current  file  transfer  finishes
              (so it may take a little time if a big file is being handled when
              the  signal  arrives).  A filename is output (if needed) followed
              by the --info=progress2 format of progress info.   If  you  don't
              know  which  of the 3 rsync processes is the client process, it's
              OK to signal all of them (since the non-client  processes  ignore
              the signal).

              CAUTION:  sending  SIGVTALRM  to  an older rsync (pre-3.2.0, June
              2020) will kill it.

       --password-file=FILE
              This option allows you to provide a  password  for  accessing  an
              rsync  daemon via a file or via standard input if FILE is -.  The
              file should contain just the password  on  the  first  line  (all
              other  lines are ignored).  Rsync will exit with an error if FILE
              is world readable or if a root-run rsync  command  finds  a  non-
              root-owned file.

              This  option  does not supply a password to a remote shell trans-
              port such as ssh; to learn how to do  that,  consult  the  remote
              shell's  documentation.   When  accessing an rsync daemon using a
              remote shell as the transport, this option only comes into effect
              after the remote shell finishes its authentication (i.e.  if  you
              have also specified a password in the daemon's config file).

       --early-input=FILE
              This  option  allows rsync to send up to 5K of data to the "early
              exec" script on its stdin.  One possible use of this data  is  to
              give  the  script a secret that can be used to mount an encrypted
              filesystem (which you should unmount in the the "post-xfer  exec"
              script).

              The daemon must be at least version 3.2.1 (June 2020).

       --list-only
              This  option  will cause the source files to be listed instead of
              transferred.  This option is inferred if there is a single source
              argument and no destination specified, so its main uses are:

              1.     to turn a copy command that includes a  destination  argu-
                     ment into a file-listing command, or

              2.     to  be  able  to  specify  more  than one source argument.
                     Note: be sure to include the destination.

              CAUTION: keep in mind that a source argument with a wild-card  is
              expanded  by  the  shell  into multiple arguments, so it is never
              safe to try to specify a single wild-card argument to try to  in-
              fer this option. A safe example is:

                  rsync -av --list-only foo* dest/

              This  option  always  uses an output format that looks similar to
              this:

                  drwxrwxr-x          4,096 2022/09/30 12:53:11 support
                  -rw-rw-r--             80 2005/01/11 10:37:37 support/Makefile

              The only option that affects  this  output  style  is  the  --hu-
              man-readable (-h) option.  The default is to output sizes as byte
              counts  with  digit  separators (in a 14-character-width column).
              Specifying at least one -h option makes  the  sizes  output  with
              unit  suffixes.   If  you  want old-style bytecount sizes without
              digit separators (and an 11-character-width column) use --no-h.

              Compatibility note: when requesting a  remote  listing  of  files
              from  an  rsync  that is version 2.6.3 or older (i.e., pre-2005),
              you may encounter an error if you ask for a  non-recursive  list-
              ing.   This  is  because a file listing implies the --dirs option
              without --recursive, and older rsyncs don't have that option.  To
              avoid this problem, either specify the --no-dirs option  (if  you
              don't need to expand a directory's content), or turn on recursion
              and exclude the content of subdirectories: -r --exclude='/*/*'.

       --bwlimit=RATE
              This  option  allows you to specify the maximum transfer rate for
              the data sent over the socket, specified  in  units  per  second.
              The  RATE  value can be suffixed with a string to indicate a size
              multiplier, and may be a fractional value (e.g.  --bwlimit=1.5m).
              If  no  suffix  is  specified, the value will be assumed to be in
              units of 1024 bytes (as if "K" or "KiB" had been appended).   See
              the --max-size option for a description of all the available suf-
              fixes.  A value of 0 specifies no limit.

              For  backward-compatibility  reasons,  the  rate  limit  will  be
              rounded to the nearest KiB unit, so no  rate  smaller  than  1024
              bytes per second is possible.

              Rsync writes data over the socket in blocks, and this option both
              limits  the  size  of  the blocks that rsync writes, and tries to
              keep the average transfer rate  at  the  requested  limit.   Some
              burstiness may be seen where rsync writes out a block of data and
              then sleeps to bring the average rate into compliance.

              Due  to the internal buffering of data, the --progress option may
              not be an accurate reflection on how fast the data is being sent.
              This is because some files can show up as being rapidly sent when
              the data is quickly buffered, while other can  show  up  as  very
              slow  when the flushing of the output buffer occurs.  This may be
              fixed in a future version.

              See also the daemon version of the --bwlimit option.

       --stop-after=MINS, (--time-limit=MINS)
              This option tells rsync to stop copying when the specified number
              of minutes has elapsed.

              For maximal flexibility, rsync does not communicate  this  option
              to  the  remote rsync since it is usually enough that one side of
              the connection quits as specified.  This allows the option's  use
              even  when  only one side of the connection supports it.  You can
              tell the remote side about the time limit  using  --remote-option
              (-M), should the need arise.

              The --time-limit version of this option is deprecated.

       --stop-at=y-m-dTh:m
              This  option tells rsync to stop copying when the specified point
              in time has been reached. The date & time can be fully  specified
              in   a   numeric   format   of  year-month-dayThour:minute  (e.g.
              2000-12-31T23:59) in the local timezone.  You may choose to sepa-
              rate the date numbers using slashes instead of dashes.

              The value can also be abbreviated in a variety of ways,  such  as
              specifying  a 2-digit year and/or leaving off various values.  In
              all cases, the value will be taken to be the next possible  point
              in  time  where  the  supplied information matches.  If the value
              specifies the current time or a past time, rsync  exits  with  an
              error.

              For  example, "1-30" specifies the next January 30th (at midnight
              local time), "14:00" specifies the next 2 P.M., "1" specifies the
              next 1st of the month at midnight, "31" specifies the next  month
              where  we  can stop on its 31st day, and ":59" specifies the next
              59th minute after the hour.

              For maximal flexibility, rsync does not communicate  this  option
              to  the  remote rsync since it is usually enough that one side of
              the connection quits as specified.  This allows the option's  use
              even  when  only one side of the connection supports it.  You can
              tell the remote side about the time limit  using  --remote-option
              (-M),  should  the  need  arise.  Do keep in mind that the remote
              host may have a different default timezone than your local host.

       --fsync
              Cause the receiving side to fsync each finished file.   This  may
              slow  down  the  transfer,  but can help to provide peace of mind
              when updating critical files.

       --write-batch=FILE
              Record a file that can later be applied to another identical des-
              tination with --read-batch.  See the "BATCH MODE" section for de-
              tails, and also the --only-write-batch option.

              This option overrides the negotiated checksum  &  compress  lists
              and  always  negotiates a choice based on old-school md5/md4/zlib
              choices.  This means batch mode is not compatible with newer com-
              pression choices such as zstd or lz4.

       --only-write-batch=FILE
              Works like --write-batch, except that no updates are made on  the
              destination system when creating the batch.  This lets you trans-
              port  the  changes to the destination system via some other means
              and then apply the changes via --read-batch.

              Note that you can feel free to write the batch directly  to  some
              portable media: if this media fills to capacity before the end of
              the  transfer,  you  can  just apply that partial transfer to the
              destination and repeat the whole process to get the rest  of  the
              changes  (as  long as you don't mind a partially updated destina-
              tion system while the multi-update cycle is happening).

              Also note that you only save bandwidth when pushing changes to  a
              remote system because this allows the batched data to be diverted
              from  the  sender into the batch file without having to flow over
              the wire to the receiver (when pulling, the sender is remote, and
              thus can't write the batch).

       --read-batch=FILE
              Apply all of the changes stored in FILE, a file previously gener-
              ated by --write-batch.  If FILE is -, the batch data will be read
              from standard input. See the "BATCH MODE" section for details.

       --protocol=NUM
              Force an older protocol version to be used.  This is  useful  for
              creating a batch file that is compatible with an older version of
              rsync.   For  instance,  if  rsync  2.6.4  is being used with the
              --write-batch option, but rsync 2.6.3 is what will be used to run
              the --read-batch option, you should use "--protocol=28" when cre-
              ating the batch file to force the older protocol  version  to  be
              used  in  the batch file (assuming you can't upgrade the rsync on
              the reading system).

       --iconv=CONVERT_SPEC
              Rsync can convert filenames between character sets using this op-
              tion.  Using a CONVERT_SPEC of "." tells rsync to look up the de-
              fault character-set via the locale setting.  Alternately, you can
              fully specify what conversion to do by giving a local and  a  re-
              mote  charset separated by a comma in the order --iconv=LOCAL,RE-
              MOTE, e.g. --iconv=utf8,iso88591.  This order  ensures  that  the
              option  will  stay  the  same  whether  you're pushing or pulling
              files.  Finally, you can specify  either  --no-iconv  or  a  CON-
              VERT_SPEC of "-" to turn off any conversion.  The default setting
              of this option is site-specific, and can also be affected via the
              RSYNC_ICONV environment variable.

              For  a  list  of what charset names your local iconv library sup-
              ports, you can run "iconv --list".

              If you specify the --secluded-args (-s) option, rsync will trans-
              late the filenames you specify on the command-line that are being
              sent to the remote host.  See also the --files-from option.

              Note that rsync does not do any conversion  of  names  in  filter
              files  (including include/exclude files).  It is up to you to en-
              sure that you're specifying matching rules that can match on both
              sides of the transfer.  For instance, you can specify  extra  in-
              clude/exclude  rules if there are filename differences on the two
              sides that need to be accounted for.

              When you pass an --iconv option to an rsync  daemon  that  allows
              it,  the  daemon uses the charset specified in its "charset" con-
              figuration parameter regardless of the remote charset  you  actu-
              ally  pass.   Thus,  you  may feel free to specify just the local
              charset for a daemon transfer (e.g.  --iconv=utf8).

       --ipv4, -4 or --ipv6, -6
              Tells rsync to prefer IPv4/IPv6 when creating sockets or  running
              ssh.   This  affects  sockets that rsync has direct control over,
              such as the outgoing socket when  directly  contacting  an  rsync
              daemon,  as  well as the forwarding of the -4 or -6 option to ssh
              when rsync can deduce that ssh is being used as the remote shell.
              For  other   remote   shells   you'll   need   to   specify   the
              "--rsh SHELL -4"  option directly (or whatever IPv4/IPv6 hint op-
              tions it uses).

              See also the daemon version of these options.

              If rsync was compiled without support for IPv6, the --ipv6 option
              will have no effect.  The  rsync --version  output  will  contain
              "no IPv6" if is the case.

       --checksum-seed=NUM
              Set  the  checksum seed to the integer NUM.  This 4 byte checksum
              seed is included in each block and MD4 file checksum  calculation
              (the  more  modern  file checksums don't use a seed).  By default
              the checksum seed is generated by the server and defaults to  the
              current  time().   This option is used to set a specific checksum
              seed, which is useful for applications that want repeatable block
              checksums, or in the case where the  user  wants  a  more  random
              checksum  seed.  Setting NUM to 0 causes rsync to use the default
              of time() for checksum seed.

DAEMON OPTIONS
       The options allowed when starting an rsync daemon are as follows:

       --daemon
              This tells rsync that it is to run as a daemon.  The  daemon  you
              start  running  may  be  accessed using an rsync client using the
              host::module or rsync://host/module/ syntax.

              If standard input is a socket then rsync will assume that  it  is
              being  run  via  inetd, otherwise it will detach from the current
              terminal and become a background daemon.  The  daemon  will  read
              the  config  file  (rsyncd.conf) on each connect made by a client
              and respond to requests accordingly.

              See the rsyncd.conf(5) manpage for more details.

       --address=ADDRESS
              By default rsync will bind to the wildcard address when run as  a
              daemon with the --daemon option.  The --address option allows you
              to  specify a specific IP address (or hostname) to bind to.  This
              makes virtual hosting possible in conjunction with  the  --config
              option.

              See also the address global option in the rsyncd.conf manpage and
              the client version of the --address option.

       --bwlimit=RATE
              This  option  allows you to specify the maximum transfer rate for
              the data the daemon sends over the socket.  The client can  still
              specify  a  smaller  --bwlimit value, but no larger value will be
              allowed.

              See the client version of the --bwlimit option for some extra de-
              tails.

       --config=FILE
              This specifies an alternate config file than the  default.   This
              is  only  relevant  when  --daemon  is specified.  The default is
              /etc/rsyncd.conf unless the daemon is running over a remote shell
              program and the remote user is not the super-user; in  that  case
              the  default  is  rsyncd.conf in the current directory (typically
              $HOME).

       --dparam=OVERRIDE, -M
              This option can be used to set  a  daemon-config  parameter  when
              starting up rsync in daemon mode.  It is equivalent to adding the
              parameter  at  the  end of the global settings prior to the first
              module's definition.  The parameter names can be specified  with-
              out spaces, if you so desire.  For instance:

                  rsync --daemon -M pidfile=/path/rsync.pid

       --no-detach
              When  running as a daemon, this option instructs rsync to not de-
              tach itself and become a background process.  This option is  re-
              quired  when running as a service on Cygwin, and may also be use-
              ful when rsync is supervised by a program such as daemontools  or
              AIX's  System Resource Controller.   --no-detach  is  also recom-
              mended when rsync is run under a debugger.  This  option  has  no
              effect if rsync is run from inetd or sshd.

       --port=PORT
              This  specifies  an  alternate  TCP port number for the daemon to
              listen on rather than the default of 873.

              See also the client version of the --port  option  and  the  port
              global setting in the rsyncd.conf manpage.

       --log-file=FILE
              This option tells the rsync daemon to use the given log-file name
              instead of using the "log file" setting in the config file.

              See also the client version of the --log-file option.

       --log-file-format=FORMAT
              This option tells the rsync daemon to use the given FORMAT string
              instead of using the "log format" setting in the config file.  It
              also  enables  "transfer logging"  unless the string is empty, in
              which case transfer logging is turned off.

              See also the client version of the --log-file-format option.

       --sockopts
              This overrides the socket options setting in the rsyncd.conf file
              and has the same syntax.

              See also the client version of the --sockopts option.

       --verbose, -v
              This option increases the amount of information the  daemon  logs
              during  its  startup  phase.  After the client connects, the dae-
              mon's verbosity level will be controlled by the options that  the
              client  used and the "max verbosity" setting in the module's con-
              fig section.

              See also the client version of the --verbose option.

       --ipv4, -4 or --ipv6, -6
              Tells rsync to prefer IPv4/IPv6 when creating the incoming  sock-
              ets  that  the  rsync  daemon will use to listen for connections.
              One of these options may be required in older versions  of  Linux
              to  work around an IPv6 bug in the kernel (if you see an "address
              already in use" error when nothing else is using  the  port,  try
              specifying --ipv6 or --ipv4 when starting the daemon).

              See also the client version of these options.

              If rsync was compiled without support for IPv6, the --ipv6 option
              will  have  no  effect.   The rsync --version output will contain
              "no IPv6" if is the case.

       --help, -h
              When specified after --daemon, print a short help page describing
              the options available for starting an rsync daemon.

FILTER RULES
       The filter rules allow for custom control  of  several  aspects  of  how
       files are handled:

       o      Control which files the sending side puts into the file list that
              describes the transfer hierarchy

       o      Control  which  files  the  receiving side protects from deletion
              when the file is not in the sender's file list

       o      Control which extended attribute names are skipped  when  copying
              xattrs

       The rules are either directly specified via option arguments or they can
       be  read in from one or more files.  The filter-rule files can even be a
       part of the hierarchy of files being copied, affecting  different  parts
       of the tree in different ways.

   SIMPLE INCLUDE/EXCLUDE RULES
       We  will  first  cover  the basics of how include & exclude rules affect
       what files are transferred, ignoring any deletion side-effects.   Filter
       rules  mainly  affect the contents of directories that rsync is "recurs-
       ing" into, but they can also affect a top-level  item  in  the  transfer
       that was specified as a argument.

       The default for any unmatched file/directory is for it to be included in
       the transfer, which puts the file/directory into the sender's file list.
       The use of an exclude rule causes one or more matching files/directories
       to  be  left out of the sender's file list.  An include rule can be used
       to limit the effect of an exclude rule that is matching too many files.

       The order of the rules is important because the first rule that  matches
       is  the  one that takes effect.  Thus, if an early rule excludes a file,
       no include rule that comes after it can have any effect. This means that
       you must place any include overrides somewhere prior to the exclude that
       it is intended to limit.

       When a directory is excluded, all its contents and sub-contents are also
       excluded.  The sender doesn't scan through any of it at all,  which  can
       save a lot of time when skipping large unneeded sub-trees.

       It  is  also  important to understand that the include/exclude rules are
       applied to every file and directory that the sender is  recursing  into.
       Thus,  if  you  want  a particular deep file to be included, you have to
       make sure that none of the directories that must be traversed on the way
       down to that file are excluded or else the file will never be discovered
       to be included. As an example, if the directory "a/path" was given as  a
       transfer   argument   and   you   want   to   ensure   that   the   file
       "a/path/down/deep/wanted.txt" is a part of the transfer, then the sender
       must  not  exclude   the   directories   "a/path",   "a/path/down",   or
       "a/path/down/deep" as it makes it way scanning through the file tree.

       When  you  are  working  on the rules, it can be helpful to ask rsync to
       tell you what is being  excluded/included  and  why.   Specifying  --de-
       bug=FILTER  or (when pulling files) -M--debug=FILTER turns on level 1 of
       the FILTER debug information that will output a message any time that  a
       file  or  directory  is  included or excluded and which rule it matched.
       Beginning in 3.2.4 it will also warn  if  a  filter  rule  has  trailing
       whitespace,  since an exclude of "foo " (with a trailing space) will not
       exclude a file named "foo".

       Exclude and include rules can specify wildcard  PATTERN  MATCHING  RULES
       (similar  to shell wildcards) that allow you to match things like a file
       suffix or a portion of a filename.

       A rule can be limited to only affecting a directory by putting a  trail-
       ing slash onto the filename.

   SIMPLE INCLUDE/EXCLUDE EXAMPLE
       With the following file tree created on the sending side:

           mkdir x/
           touch x/file.txt
           mkdir x/y/
           touch x/y/file.txt
           touch x/y/zzz.txt
           mkdir x/z/
           touch x/z/file.txt

       Then  the  following rsync command will transfer the file "x/y/file.txt"
       and  the  directories  needed  to  hold  it,  resulting  in   the   path
       "/tmp/x/y/file.txt" existing on the remote host:

           rsync -ai -f'+ x/' -f'+ x/y/' -f'+ x/y/file.txt' -f'- *' x host:/tmp/

       Aside:  this  copy could also have been accomplished using the -R option
       (though the 2 commands behave differently if deletions are enabled):

           rsync -aiR x/y/file.txt host:/tmp/

       The following command does not need an include of the "x" directory  be-
       cause  it is not a part of the transfer (note the trailing slash).  Run-
       ning this command would copy just "/tmp/x/file.txt" because the "y"  and
       "z" directories get excluded:

           rsync -ai -f'+ file.txt' -f'- *' x/ host:/tmp/x/

       This  command  would  omit the zzz.txt file while copying "x" and every-
       thing else it contains:

           rsync -ai -f'- zzz.txt' x host:/tmp/

   FILTER RULES WHEN DELETING
       By default the include & exclude filter rules affect both the sender (as
       it creates its file list) and the receiver (as it creates its file lists
       for calculating deletions).  If no delete option is in effect,  the  re-
       ceiver skips creating the delete-related file lists.  This two-sided de-
       fault  can be manually overridden so that you are only specifying sender
       rules or receiver rules, as described in the FILTER RULES IN DEPTH  sec-
       tion.

       When  deleting, an exclude protects a file from being removed on the re-
       ceiving side while an include overrides  that  protection  (putting  the
       file  at  risk  of deletion). The default is for a file to be at risk --
       its safety depends on it matching a corresponding file from the sender.

       An example of the two-sided exclude effect can  be  illustrated  by  the
       copying  of  a  C development directory between 2 systems.  When doing a
       touch-up copy, you might want to skip copying the built  executable  and
       the  .o  files  (sender hide) so that the receiving side can build their
       own and not lose any object files that  are  already  correct  (receiver
       protect).  For instance:

           rsync -ai --del -f'- *.o' -f'- cmd' src host:/dest/

       Note  that  using -f'-p *.o' is even better than -f'- *.o' if there is a
       chance that the directory structure may have changed.  The "p"  modifier
       is discussed in FILTER RULE MODIFIERS.

       One  final  note,  if  your shell doesn't mind unexpanded wildcards, you
       could simplify the typing of the filter options by using  an  underscore
       in  place  of  the  space  and  leaving  off  the quotes.  For instance,
       -f -_*.o -f -_cmd (and similar) could be used instead of the filter  op-
       tions above.

   FILTER RULES IN DEPTH
       Rsync  supports  old-style  include/exclude  rules  and new-style filter
       rules.  The older rules are specified using --include and  --exclude  as
       well  as the --include-from and --exclude-from. These are limited in be-
       havior but they don't require a "-" or "+" prefix.  An old-style exclude
       rule is turned into a "- name" filter rule (with no  modifiers)  and  an
       old-style  include  rule  is turned into a "+ name" filter rule (with no
       modifiers).

       Rsync builds an ordered list of filter rules as specified  on  the  com-
       mand-line  and/or  read-in  from files.  New style filter rules have the
       following syntax:

           RULE [PATTERN_OR_FILENAME]
           RULE,MODIFIERS [PATTERN_OR_FILENAME]

       You have your choice of using either short or long RULE  names,  as  de-
       scribed  below.   If  you use a short-named rule, the ',' separating the
       RULE from the MODIFIERS is optional.  The PATTERN or FILENAME that  fol-
       lows  (when  present) must come after either a single space or an under-
       score (_). Any additional spaces and/or underscores are considered to be
       a part of the pattern name.  Here are the available rule prefixes:

       exclude, '-'
              specifies an exclude pattern that (by default) is both a hide and
              a protect.

       include, '+'
              specifies an include pattern that (by default) is both a show and
              a risk.

       merge, '.'
              specifies a merge-file on the client side to read for more rules.

       dir-merge, ':'
              specifies a per-directory merge-file.  Using this kind of  filter
              rule  requires that you trust the sending side's filter checking,
              so it has the side-effect mentioned under the --trust-sender  op-
              tion.

       hide, 'H'
              specifies  a pattern for hiding files from the transfer.  Equiva-
              lent to a sender-only exclude, so -f'H foo' could also be  speci-
              fied as -f'-s foo'.

       show, 'S'
              files  that  match  the  pattern  are not hidden. Equivalent to a
              sender-only include, so -f'S foo'  could  also  be  specified  as
              -f'+s foo'.

       protect, 'P'
              specifies  a pattern for protecting files from deletion.  Equiva-
              lent to a receiver-only exclude, so -f'P foo' could also be spec-
              ified as -f'-r foo'.

       risk, 'R'
              files that match the pattern are not protected. Equivalent  to  a
              receiver-only  include,  so  -f'R foo' could also be specified as
              -f'+r foo'.

       clear, '!'
              clears the current include/exclude list (takes no argument)

       When rules are being read from a file (using merge or dir-merge),  empty
       lines  are  ignored,  as  are  whole-line comments that start with a '#'
       (filename rules that contain a hash character are unaffected).

       Note also that the --filter, --include, and --exclude options  take  one
       rule/pattern  each.  To add multiple ones, you can repeat the options on
       the command-line, use the merge-file syntax of the --filter  option,  or
       the --include-from / --exclude-from options.

   PATTERN MATCHING RULES
       Most  of  the rules mentioned above take an argument that specifies what
       the rule should match.  If rsync is recursing through a directory  hier-
       archy,  keep  in  mind  that each pattern is matched against the name of
       every directory in the descent path as  rsync  finds  the  filenames  to
       send.

       The matching rules for the pattern argument take several forms:

       o      If  a  pattern  contains a / (not counting a trailing slash) or a
              "**" (which can match a  slash),  then  the  pattern  is  matched
              against  the  full  pathname,  including  any leading directories
              within the transfer.  If the  pattern  doesn't  contain  a  (non-
              trailing)  / or a "**", then it is matched only against the final
              component of the filename or pathname.  For  example,  foo  means
              that  the  final path component must be "foo" while foo/bar would
              match the last 2 elements of the path (as long as  both  elements
              are within the transfer).

       o      A pattern that ends with a / only matches a directory, not a reg-
              ular file, symlink, or device.

       o      A  pattern  that  starts with a / is anchored to the start of the
              transfer path instead  of  the  end.   For  example,  /foo/**  or
              /foo/bar/** match only leading elements in the path.  If the rule
              is read from a per-directory filter file, the transfer path being
              matched will begin at the level of the filter file instead of the
              top  of  the  transfer.  See the section on ANCHORING INCLUDE/EX-
              CLUDE PATTERNS for a full discussion of how to specify a  pattern
              that matches at the root of the transfer.

       Rsync  chooses between doing a simple string match and wildcard matching
       by checking if the pattern contains one of these three wildcard  charac-
       ters: '*', '?', and '[' :

       o      a '?' matches any single character except a slash (/).

       o      a '*' matches zero or more non-slash characters.

       o      a '**' matches zero or more characters, including slashes.

       o      a '[' introduces a character class, such as [a-z] or [[:alpha:]],
              that must match one character.

       o      a  trailing  *** in the pattern is a shorthand that allows you to
              match a directory and all its contents using a single rule.   For
              example, specifying "dir_name/***" will match both the "dir_name"
              directory  (as  if "dir_name/" had been specified) and everything
              in the directory (as if "dir_name/**" had been specified).

       o      a backslash can be used to escape a wildcard character, but it is
              only interpreted as an escape character if at least one  wildcard
              character is present in the match pattern. For instance, the pat-
              tern "foo\bar" matches that single backslash literally, while the
              pattern  "foo\bar*"  would  need  to be changed to "foo\\bar*" to
              avoid the "\b" becoming just "b".

       Here are some examples of exclude/include matching:

       o      Option -f'- *.o' would exclude all filenames ending with .o

       o      Option -f'- /foo' would exclude a file (or directory)  named  foo
              in the transfer-root directory

       o      Option -f'- foo/' would exclude any directory named foo

       o      Option -f'- foo/*/bar' would exclude any file/directory named bar
              which  is at two levels below a directory named foo (if foo is in
              the transfer)

       o      Option -f'- /foo/**/bar' would exclude any  file/directory  named
              bar that was two or more levels below a top-level directory named
              foo (note that /foo/bar is not excluded by this)

       o      Options  -f'+ */' -f'+ *.c' -f'- *' would include all directories
              and .c source files but nothing else

       o      Options -f'+ foo/' -f'+ foo/bar.c' -f'- *' would include only the
              foo directory and foo/bar.c (the foo directory must be explicitly
              included or it would be excluded by the "- *")

   FILTER RULE MODIFIERS
       The following modifiers are accepted after an include (+) or exclude (-)
       rule:

       o      A / specifies that the include/exclude  rule  should  be  matched
              against  the absolute pathname of the current item.  For example,
              -f'-/ /etc/passwd' would exclude the passwd  file  any  time  the
              transfer  was  sending  files  from the "/etc" directory, and "-/
              subdir/foo" would always exclude "foo" when it is in a  directory
              named  "subdir",  even  if  "foo"  is  at the root of the current
              transfer.

       o      A ! specifies that the include/exclude should take effect if  the
              pattern  fails  to  match.  For instance, -f'-! */' would exclude
              all non-directories.

       o      A C is used to indicate that all  the  global  CVS-exclude  rules
              should be inserted as excludes in place of the "-C".  No argument
              should follow.

       o      An  s  is  used  to indicate that the rule applies to the sending
              side.  When a rule affects the  sending  side,  it  affects  what
              files  are put into the sender's file list.  The default is for a
              rule to affect both sides unless --delete-excluded was specified,
              in which case default rules become sender-side  only.   See  also
              the  hide  (H)  and show (S) rules, which are an alternate way to
              specify sending-side includes/excludes.

       o      An r is used to indicate that the rule applies to  the  receiving
              side.   When a rule affects the receiving side, it prevents files
              from being deleted.  See the s modifier for more info.  See  also
              the protect (P) and risk (R) rules, which are an alternate way to
              specify receiver-side includes/excludes.

       o      A  p  indicates that a rule is perishable, meaning that it is ig-
              nored in directories that are being deleted.  For  instance,  the
              --cvs-exclude  (-C)  option's  default  rules that exclude things
              like "CVS" and "*.o" are marked as perishable, and will not  pre-
              vent  a  directory  that  was  removed  on  the source from being
              deleted on the destination.

       o      An  x  indicates  that  a  rule  affects  xattr  names  in  xattr
              copy/delete   operations  (and  is  thus  ignored  when  matching
              file/directory names).  If no xattr-matching rules are specified,
              a default xattr filtering rule is used (see the --xattrs option).

   MERGE-FILE FILTER RULES
       You can merge whole files into your filter rules by specifying either  a
       merge  (.)  or  a dir-merge (:) filter rule (as introduced in the FILTER
       RULES section above).

       There are two kinds of merged files -- single-instance ('.') and per-di-
       rectory (':').  A single-instance merge file is read one time,  and  its
       rules  are  incorporated  into  the  filter list in the place of the "."
       rule.  For per-directory merge files, rsync will  scan  every  directory
       that it traverses for the named file, merging its contents when the file
       exists  into  the  current list of inherited rules.  These per-directory
       rule files must be created on the sending side because it is the sending
       side that is being scanned for the available files to  transfer.   These
       rule  files may also need to be transferred to the receiving side if you
       want them to affect what files  don't  get  deleted  (see  PER-DIRECTORY
       RULES AND DELETE below).

       Some examples:

           merge /etc/rsync/default.rules
           . /etc/rsync/default.rules
           dir-merge .per-dir-filter
           dir-merge,n- .non-inherited-per-dir-excludes
           :n- .non-inherited-per-dir-excludes

       The following modifiers are accepted after a merge or dir-merge rule:

       o      A  -  specifies that the file should consist of only exclude pat-
              terns, with no other rule-parsing except for in-file comments.

       o      A + specifies that the file should consist of only  include  pat-
              terns, with no other rule-parsing except for in-file comments.

       o      A  C  is  a way to specify that the file should be read in a CVS-
              compatible manner.  This turns on 'n', 'w', and '-', but also al-
              lows the list-clearing token (!) to be specified.  If no filename
              is provided, ".cvsignore" is assumed.

       o      A e will exclude the merge-file  name  from  the  transfer;  e.g.
              "dir-merge,e .rules" is like "dir-merge .rules" and "- .rules".

       o      An  n  specifies  that the rules are not inherited by subdirecto-
              ries.

       o      A w specifies that the rules are word-split on whitespace instead
              of the normal line-splitting.   This  also  turns  off  comments.
              Note:  the  space  that  separates  the  prefix  from the rule is
              treated specially, so "- foo + bar" is parsed as two  rules  (as-
              suming that prefix-parsing wasn't also disabled).

       o      You  may  also  specify  any  of the modifiers for the "+" or "-"
              rules (above) in order to have the rules that are  read  in  from
              the  file  default  to having that modifier set (except for the !
              modifier, which would not be useful).   For  instance,  "merge,-/
              .excl"  would  treat  the  contents of .excl as absolute-path ex-
              cludes, while "dir-merge,s .filt" and ":sC" would each  make  all
              their per-directory rules apply only on the sending side.  If the
              merge  rule specifies sides to affect (via the s or r modifier or
              both), then the rules in the file must not specify sides  (via  a
              modifier or a rule prefix such as hide).

       Per-directory rules are inherited in all subdirectories of the directory
       where  the  merge-file was found unless the 'n' modifier was used.  Each
       subdirectory's rules are prefixed to the inherited  per-directory  rules
       from  its  parents,  which gives the newest rules a higher priority than
       the inherited rules.  The entire set of dir-merge rules are grouped  to-
       gether in the spot where the merge-file was specified, so it is possible
       to override dir-merge rules via a rule that got specified earlier in the
       list  of global rules.  When the list-clearing rule ("!") is read from a
       per-directory file, it only clears the inherited rules for  the  current
       merge file.

       Another  way  to  prevent a single rule from a dir-merge file from being
       inherited is to anchor it with a leading slash.   Anchored  rules  in  a
       per-directory  merge-file are relative to the merge-file's directory, so
       a pattern "/foo" would only match the file "foo" in the directory  where
       the dir-merge filter file was found.

       Here's an example filter file which you'd specify via --filter=". file":

           merge /home/user/.global-filter
           - *.gz
           dir-merge .rules
           + *.[ch]
           - *.o
           - foo*

       This  will  merge  the contents of the /home/user/.global-filter file at
       the start of the list and also turns the ".rules" filename into  a  per-
       directory  filter file.  All rules read in prior to the start of the di-
       rectory scan follow the global anchoring rules  (i.e.  a  leading  slash
       matches at the root of the transfer).

       If  a per-directory merge-file is specified with a path that is a parent
       directory of the first transfer directory, rsync will scan all the  par-
       ent  directories  from that starting point to the transfer directory for
       the indicated per-directory file.  For instance, here is a common filter
       (see -F):

           --filter=': /.rsync-filter'

       That rule tells rsync to scan for the file .rsync-filter in all directo-
       ries from the root down through the parent  directory  of  the  transfer
       prior  to  the start of the normal directory scan of the file in the di-
       rectories that are sent as a part of the transfer. (Note: for  an  rsync
       daemon, the root is always the same as the module's "path".)

       Some examples of this pre-scanning for per-directory files:

           rsync -avF /src/path/ /dest/dir
           rsync -av --filter=': ../../.rsync-filter' /src/path/ /dest/dir
           rsync -av --filter=': .rsync-filter' /src/path/ /dest/dir

       The  first  two  commands above will look for ".rsync-filter" in "/" and
       "/src" before the normal scan begins looking for the file in "/src/path"
       and its subdirectories.  The last command  avoids  the  parent-directory
       scan and only looks for the ".rsync-filter" files in each directory that
       is a part of the transfer.

       If  you want to include the contents of a ".cvsignore" in your patterns,
       you should use the rule ":C", which creates a dir-merge of  the  .cvsig-
       nore  file,  but parsed in a CVS-compatible manner.  You can use this to
       affect where the --cvs-exclude (-C) option's inclusion of the per-direc-
       tory .cvsignore file gets placed into your rules  by  putting  the  ":C"
       wherever  you  like in your filter rules.  Without this, rsync would add
       the dir-merge rule for the .cvsignore file at the end of all your  other
       rules  (giving  it  a lower priority than your command-line rules).  For
       example:

           cat <<EOT | rsync -avC --filter='. -' a/ b
           + foo.o
           :C
           - *.old
           EOT
           rsync -avC --include=foo.o -f :C --exclude='*.old' a/ b

       Both of the above rsync commands are identical.  Each one will merge all
       the per-directory .cvsignore rules in the middle of the list rather than
       at the end.  This allows their directory-specific rules to supersede the
       rules that follow the :C instead of being subservient to all your rules.
       To affect the other CVS exclude rules (i.e. the default list  of  exclu-
       sions,  the  contents  of $HOME/.cvsignore, and the value of $CVSIGNORE)
       you should omit the -C command-line option and  instead  insert  a  "-C"
       rule into your filter rules; e.g.  "--filter=-C".

   LIST-CLEARING FILTER RULE
       You  can  clear the current include/exclude list by using the "!" filter
       rule (as introduced in the FILTER RULES section above).   The  "current"
       list  is  either  the  global  list of rules (if the rule is encountered
       while parsing the filter options) or a set of per-directory rules (which
       are inherited in their own sub-list, so a subdirectory can use  this  to
       clear out the parent's rules).

   ANCHORING INCLUDE/EXCLUDE PATTERNS
       As  mentioned  earlier,  global include/exclude patterns are anchored at
       the "root of the transfer" (as opposed to per-directory patterns,  which
       are anchored at the merge-file's directory).  If you think of the trans-
       fer  as  a subtree of names that are being sent from sender to receiver,
       the transfer-root is where the tree starts to be duplicated in the  des-
       tination  directory.  This root governs where patterns that start with a
       / match.

       Because the matching is relative  to  the  transfer-root,  changing  the
       trailing  slash  on a source path or changing your use of the --relative
       option affects the path you need to use in your matching (in addition to
       changing how much of the file tree  is  duplicated  on  the  destination
       host).  The following examples demonstrate this.

       Let's  say  that we want to match two source files, one with an absolute
       path of "/home/me/foo/bar", and one with a path of  "/home/you/bar/baz".
       Here is how the various command choices differ for a 2-source transfer:

           Example cmd: rsync -a /home/me /home/you /dest
           +/- pattern: /me/foo/bar
           +/- pattern: /you/bar/baz
           Target file: /dest/me/foo/bar
           Target file: /dest/you/bar/baz

           Example cmd: rsync -a /home/me/ /home/you/ /dest
           +/- pattern: /foo/bar               (note missing "me")
           +/- pattern: /bar/baz               (note missing "you")
           Target file: /dest/foo/bar
           Target file: /dest/bar/baz

           Example cmd: rsync -a --relative /home/me/ /home/you /dest
           +/- pattern: /home/me/foo/bar       (note full path)
           +/- pattern: /home/you/bar/baz      (ditto)
           Target file: /dest/home/me/foo/bar
           Target file: /dest/home/you/bar/baz

           Example cmd: cd /home; rsync -a --relative me/foo you/ /dest
           +/- pattern: /me/foo/bar      (starts at specified path)
           +/- pattern: /you/bar/baz     (ditto)
           Target file: /dest/me/foo/bar
           Target file: /dest/you/bar/baz

       The  easiest  way  to see what name you should filter is to just look at
       the output when using --verbose and put a / in front of  the  name  (use
       the --dry-run option if you're not yet ready to copy any files).

   PER-DIRECTORY RULES AND DELETE
       Without  a  delete  option, per-directory rules are only relevant on the
       sending side, so you can feel free to exclude the merge files themselves
       without affecting the transfer.  To make this  easy,  the  'e'  modifier
       adds this exclude for you, as seen in these two equivalent commands:

           rsync -av --filter=': .excl' --exclude=.excl host:src/dir /dest
           rsync -av --filter=':e .excl' host:src/dir /dest

       However,  if  you want to do a delete on the receiving side AND you want
       some files to be excluded from being deleted, you'll  need  to  be  sure
       that the receiving side knows what files to exclude.  The easiest way is
       to  include  the  per-directory  merge  files  in  the  transfer and use
       --delete-after, because this ensures that the receiving  side  gets  all
       the  same  exclude  rules  as the sending side before it tries to delete
       anything:

           rsync -avF --delete-after host:src/dir /dest

       However, if the merge files are not a part of the transfer, you'll  need
       to  either specify some global exclude rules (i.e. specified on the com-
       mand line), or you'll need to  maintain  your  own  per-directory  merge
       files  on  the  receiving side.  An example of the first is this (assume
       that the remote .rules files exclude themselves):

           rsync -av --filter=': .rules' --filter='. /my/extra.rules'
              --delete host:src/dir /dest

       In the above example the extra.rules file can affect both sides  of  the
       transfer,  but  (on  the  sending side) the rules are subservient to the
       rules merged from the .rules files because they were specified after the
       per-directory merge rule.

       In one final example, the remote side  is  excluding  the  .rsync-filter
       files  from the transfer, but we want to use our own .rsync-filter files
       to control what gets deleted on the receiving side.  To do this we  must
       specifically  exclude  the per-directory merge files (so that they don't
       get deleted) and then put rules into the local  files  to  control  what
       else should not get deleted.  Like one of these commands:

           rsync -av --filter=':e /.rsync-filter' --delete \
               host:src/dir /dest
           rsync -avFF --delete host:src/dir /dest

TRANSFER RULES
       In  addition  to  the  FILTER RULES that affect the recursive file scans
       that generate the file list on the sending and (when deleting) receiving
       sides, there are transfer rules. These rules affect which files the gen-
       erator decides need to be transferred without the side effects of an ex-
       clude filter rule.  Transfer rules affect only files and never  directo-
       ries.

       Because a transfer rule does not affect what goes into the sender's (and
       receiver's)  file  list,  it  cannot  have any effect on which files get
       deleted on the receiving side.   For  example,  if  the  file  "foo"  is
       present in the sender's list but its size is such that it is omitted due
       to  a transfer rule, the receiving side does not request the file.  How-
       ever, its presence in the file list means that a delete  pass  will  not
       remove  a matching file named "foo" on the receiving side.  On the other
       hand, a server-side exclude (hide) of the file "foo" leaves the file out
       of the server's file list, and absent a receiver-side exclude  (protect)
       the  receiver  will  remove a matching file named "foo" if deletions are
       requested.

       Given  that  the  files  are  still  in  the  sender's  file  list,  the
       --prune-empty-dirs option will not judge a directory as being empty even
       if it contains only files that the transfer rules omitted.

       Similarly, a transfer rule does not have any extra effect on which files
       are  deleted  on  the receiving side, so setting a maximum file size for
       the transfer does not prevent big files from being deleted.

       Examples of transfer rules include the default "quick  check"  algorithm
       (which compares size & modify time), the --update option, the --max-size
       option, the --ignore-non-existing option, and a few others.

BATCH MODE
       Batch  mode can be used to apply the same set of updates to many identi-
       cal systems.  Suppose one has a tree which is replicated on a number  of
       hosts.   Now suppose some changes have been made to this source tree and
       those changes need to be propagated to the other hosts.  In order to  do
       this using batch mode, rsync is run with the write-batch option to apply
       the  changes  made  to  the source tree to one of the destination trees.
       The write-batch option causes the rsync client  to  store  in  a  "batch
       file" all the information needed to repeat this operation against other,
       identical destination trees.

       Generating  the batch file once saves having to perform the file status,
       checksum, and data block generation more than once when updating  multi-
       ple  destination  trees.   Multicast  transport protocols can be used to
       transfer the batch update files in parallel to many hosts at  once,  in-
       stead of sending the same data to every host individually.

       To  apply  the  recorded  changes to another destination tree, run rsync
       with the read-batch option, specifying the name of the same batch  file,
       and  the destination tree.  Rsync updates the destination tree using the
       information stored in the batch file.

       For your convenience, a script file is also created when the write-batch
       option is used: it will be named the same as the batch file  with  ".sh"
       appended.   This script file contains a command line suitable for updat-
       ing a destination tree using the associated batch file.  It can be  exe-
       cuted  using  a  Bourne (or Bourne-like) shell, optionally passing in an
       alternate destination tree pathname which is then used  instead  of  the
       original  destination  path.   This  is useful when the destination tree
       path on the current host differs from the one used to create  the  batch
       file.

       Examples:

           $ rsync --write-batch=foo -a host:/source/dir/ /adest/dir/
           $ scp foo* remote:
           $ ssh remote ./foo.sh /bdest/dir/

           $ rsync --write-batch=foo -a /source/dir/ /adest/dir/
           $ ssh remote rsync --read-batch=- -a /bdest/dir/ <foo

       In these examples, rsync is used to update /adest/dir/ from /source/dir/
       and  the  information  to  repeat  this operation is stored in "foo" and
       "foo.sh".  The host "remote" is then updated with the batched data going
       into the directory /bdest/dir.  The differences between the two examples
       reveals some of the flexibility you have in how you deal with batches:

       o      The first example shows that the initial copy doesn't have to  be
              local --  you  can  push or pull data to/from a remote host using
              either the remote-shell syntax or rsync  daemon  syntax,  as  de-
              sired.

       o      The first example uses the created "foo.sh" file to get the right
              rsync  options  when running the read-batch command on the remote
              host.

       o      The second example reads the batch data  via  standard  input  so
              that  the  batch file doesn't need to be copied to the remote ma-
              chine first.  This example avoids the foo.sh  script  because  it
              needed  to use a modified --read-batch option, but you could edit
              the script file if you wished to make use of  it  (just  be  sure
              that no other option is trying to use standard input, such as the
              --exclude-from=- option).

       Caveats:

       The  read-batch  option expects the destination tree that it is updating
       to be identical to the destination tree that  was  used  to  create  the
       batch  update  fileset.  When a difference between the destination trees
       is encountered the update might be discarded with a warning (if the file
       appears to be up-to-date already) or the file-update  may  be  attempted
       and  then, if the file fails to verify, the update discarded with an er-
       ror.  This means that it should be safe to re-run a read-batch operation
       if the command got interrupted.  If you wish to force the batched-update
       to always be attempted regardless of the file's size and date,  use  the
       -I option (when reading the batch).  If an error occurs, the destination
       tree will probably be in a partially updated state.  In that case, rsync
       can  be  used in its regular (non-batch) mode of operation to fix up the
       destination tree.

       The rsync version used on all destinations must be at least  as  new  as
       the  one  used to generate the batch file.  Rsync will die with an error
       if the protocol version in the batch file is too new for the batch-read-
       ing rsync to handle.  See also the --protocol option for a way  to  have
       the  creating rsync generate a batch file that an older rsync can under-
       stand.  (Note that batch files changed format in version 2.6.3  (Septem-
       ber  2004),  so mixing versions older than that with newer versions will
       not work.)

       When reading a batch file, rsync will force the value of certain options
       to match the data in the batch file if you didn't set them to  the  same
       as  the  batch-writing  command.   Other  options  can  (and  should) be
       changed.   For   instance   --write-batch   changes   to   --read-batch,
       --files-from  is  dropped,  and the --filter / --include / --exclude op-
       tions are not needed unless one of the --delete options is specified.

       The code that  creates  the  BATCH.sh  file  transforms  any  filter/in-
       clude/exclude  options  into  a single list that is appended as a "here"
       document to the shell script file.  An advanced user  can  use  this  to
       modify  the exclude list if a change in what gets deleted by --delete is
       desired.  A normal user can ignore this detail and just  use  the  shell
       script  as  an  easy way to run the appropriate --read-batch command for
       the batched data.

SYMBOLIC LINKS
       Three basic behaviors are possible when rsync encounters a symbolic link
       in the source directory.

       By default, symbolic links are not transferred at all.  A message "skip-
       ping non-regular" file is emitted for any symlinks that exist.

       If --links is specified, then symlinks are added to  the  transfer  (in-
       stead of being noisily ignored), and the default handling is to recreate
       them  with  the same target on the destination.  Note that --archive im-
       plies --links.

       If --copy-links is specified, then symlinks are "collapsed"  by  copying
       their referent, rather than the symlink.

       Rsync can also distinguish "safe" and "unsafe" symbolic links.  An exam-
       ple  where this might be used is a web site mirror that wishes to ensure
       that the rsync module that is copied does not include symbolic links  to
       /etc/passwd  in  the  public  section  of  the  site.   Using --copy-un-
       safe-links will cause any links to be copied as the file they  point  to
       on  the  destination.   Using --safe-links will cause unsafe links to be
       omitted by the receiver.  (Note that you must specify or  imply  --links
       for --safe-links to have any effect.)

       Symbolic  links  are  considered  unsafe  if  they are absolute symlinks
       (start with /), empty, or if they contain enough ".." components to  as-
       cend from the top of the transfer.

       Here's  a  summary of how the symlink options are interpreted.  The list
       is in order of precedence, so if your combination of options isn't  men-
       tioned, use the first line that is a complete subset of your options:

       --copy-links
              Turn  all  symlinks into normal files and directories (leaving no
              symlinks in the transfer for any other options to affect).

       --copy-dirlinks
              Turn just symlinks to directories into real directories,  leaving
              all other symlinks to be handled as described below.

       --links --copy-unsafe-links
              Turn all unsafe symlinks into files and create all safe symlinks.

       --copy-unsafe-links
              Turn  all  unsafe symlinks into files, noisily skip all safe sym-
              links.

       --links --safe-links
              The receiver skips creating unsafe symlinks found in the transfer
              and creates the safe ones.

       --links
              Create all symlinks.

       For the effect of --munge-links, see the  discussion  in  that  option's
       section.

       Note  that  the  --keep-dirlinks  option does not affect symlinks in the
       transfer but instead affects how rsync treats a symlink to  a  directory
       that  already  exists  on the receiving side.  See that option's section
       for a warning.

DIAGNOSTICS
       Rsync occasionally produces error messages that may seem a little  cryp-
       tic.   The  one that seems to cause the most confusion is "protocol ver-
       sion mismatch -- is your shell clean?".

       This message is usually caused by your startup scripts or  remote  shell
       facility  producing  unwanted  garbage on the stream that rsync is using
       for its transport.  The way to diagnose this problem is to run your  re-
       mote shell like this:

           ssh remotehost /bin/true > out.dat

       then  look  at out.dat.  If everything is working correctly then out.dat
       should be a zero length file.  If you are getting the above  error  from
       rsync  then  you  will  probably find that out.dat contains some text or
       data.  Look at the contents and try to work out what  is  producing  it.
       The  most  common  cause is incorrectly configured shell startup scripts
       (such as .cshrc or .profile) that contain output statements for  non-in-
       teractive logins.

       If you are having trouble debugging filter patterns, then try specifying
       the -vv option.  At this level of verbosity rsync will show why each in-
       dividual file is included or excluded.

EXIT VALUES
       o      0 - Success

       o      1 - Syntax or usage error

       o      2 - Protocol incompatibility

       o      3 - Errors selecting input/output files, directories

       o

              o      4 - Requested action not supported. Either:

                     an  attempt was made to manipulate 64-bit files on a plat-
                     form that cannot support them

              o      an option was specified that is supported  by  the  client
                     and not by the server

       o      5 - Error starting client-server protocol

       o      10 - Error in socket I/O

       o      11 - Error in file I/O

       o      12 - Error in rsync protocol data stream

       o      13 - Errors with program diagnostics

       o      14 - Error in IPC code

       o      15 - Sibling process crashed (e.g. core dumped).

       o      16 - Sibling process was killed by a signal.

       o      19 - Received SIGUSR1.

       o      20 - Received SIGINT, SIGTERM, or SIGHUP.

       o      21 - Some error returned by waitpid()

       o      22 - Error allocating core memory buffers

       o      23 - Partial transfer due to error

       o      24 - Partial transfer due to vanished source files

       o      25 - The --max-delete limit stopped deletions

       o      30 - Timeout in data send/receive

       o      35 - Timeout waiting for daemon connection

ENVIRONMENT VARIABLES
       CVSIGNORE
              The  CVSIGNORE  environment  variable supplements any ignore pat-
              terns in .cvsignore files.  See the --cvs-exclude option for more
              details.

       RSYNC_ICONV
              Specify a default --iconv setting using  this  environment  vari-
              able.

       RSYNC_OLD_ARGS
              Specify  a "1" if you want the --old-args option to be enabled by
              default, a "2" (or more) if you want it to be enabled in the  re-
              peated-option state, or a "0" to make sure that it is disabled by
              default.  When  this  environment  variable  is set to a non-zero
              value, it supersedes the RSYNC_PROTECT_ARGS variable.

              This variable is ignored if --old-args, --no-old-args,  or  --se-
              cluded-args is specified on the command line.

              First supported in 3.2.4 (April 2022).

       RSYNC_PROTECT_ARGS
              Specify  a non-zero numeric value if you want the --secluded-args
              option to be enabled by default, or a zero  value  to  make  sure
              that it is disabled by default.

              This  variable is ignored if --secluded-args, --no-secluded-args,
              or --old-args is specified on the command line.

              Starting in 3.2.4 (April  2022),  this  variable  is  ignored  if
              RSYNC_OLD_ARGS is set to a non-zero value.

       RSYNC_RSH
              This  environment  variable  allows  you  to override the default
              shell used as the transport for rsync.  Command line options  are
              permitted  after  the command name, just as in the --rsh (-e) op-
              tion.

       RSYNC_PROXY
              This environment variable  allows  you  to  redirect  your  rsync
              client  to  use  a  web proxy when connecting to an rsync daemon.
              You should set RSYNC_PROXY to a hostname:port pair.

       RSYNC_PASSWORD
              This environment variable allows you to set the password  for  an
              rsync  daemon connection, which avoids the password prompt.  Note
              that this does not supply a password to a remote shell  transport
              such as ssh (consult its documentation for how to do that).

       USER or LOGNAME
              The  USER  or LOGNAME environment variables are used to determine
              the default username sent to an rsync daemon.  If neither is set,
              the username defaults to "nobody".  If both are set,  USER  takes
              precedence.

       RSYNC_PARTIAL_DIR
              This  environment  variable  specifies the directory to use for a
              --partial transfer without implying that partial transfers be en-
              abled.  See the --partial-dir option for full details.

       RSYNC_COMPRESS_LIST
              This environment variable allows you to customize the negotiation
              of the compression algorithm by specifying an alternate order  or
              a  reduced list of names.  Use the command rsync --version to see
              the available compression names.  See the --compress  option  for
              full details.

       RSYNC_CHECKSUM_LIST
              This environment variable allows you to customize the negotiation
              of  the  checksum algorithm by specifying an alternate order or a
              reduced list of names.  Use the command  rsync --version  to  see
              the  available  checksum names.  See the --checksum-choice option
              for full details.

       RSYNC_MAX_ALLOC
              This environment variable sets an allocation maximum  as  if  you
              had used the --max-alloc option.

       RSYNC_PORT
              This  environment  variable  is not read by rsync, but is instead
              set in its sub-environment when rsync is running the remote shell
              in combination with a daemon connection.  This  allows  a  script
              such  as  rsync-ssl  to  be able to know the port number that the
              user specified on the command line.

       HOME   This environment variable is used  to  find  the  user's  default
              .cvsignore file.

       RSYNC_CONNECT_PROG
              This  environment  variable is mainly used in debug setups to set
              the program to use when making a daemon connection.  See CONNECT-
              ING TO AN RSYNC DAEMON for full details.

       RSYNC_SHELL
              This environment variable is mainly used in debug setups  to  set
              the  program  to  use  to run the program specified by RSYNC_CON-
              NECT_PROG.  See CONNECTING TO AN RSYNC DAEMON for full details.

FILES
       /etc/rsyncd.conf or rsyncd.conf

SEE ALSO
       rsync-ssl(1), rsyncd.conf(5), rrsync(1)

BUGS
       o      Times are transferred as *nix time_t values.

       o      When transferring to FAT filesystems rsync may re-sync unmodified
              files.  See the comments on the --modify-window option.

       o      File permissions, devices, etc. are transferred as native numeri-
              cal values.

       o      See also the comments on the --delete option.

       Please report bugs! See the web site at ]8;;https://rsync.samba.org/\https://rsync.samba.org/]8;;\.

VERSION
       This manpage is current for version 3.5.0 of rsync.

INTERNAL OPTIONS
       The options --server and --sender are  used  internally  by  rsync,  and
       should never be typed by a user under normal circumstances.  Some aware-
       ness  of  these options may be needed in certain scenarios, such as when
       setting up a login that can only run an rsync  command.   For  instance,
       the  support  directory  of the rsync distribution has an example script
       named rrsync (for restricted rsync) that can be used with  a  restricted
       ssh login.

CREDITS
       Rsync is distributed under the GNU General Public License.  See the file
       COPYING for details.

       An  rsync  web  site is available at ]8;;https://rsync.samba.org/\https://rsync.samba.org/]8;;\.  The site
       includes an FAQ-O-Matic which may cover  questions  unanswered  by  this
       manual page.

       The rsync github project is ]8;;https://github.com/RsyncProject/rsync\https://github.com/RsyncProject/rsync]8;;\.

       We would be delighted to hear from you if you like this program.  Please
       contact the mailing-list at ]8;;mailto:rsync@lists.samba.org\rsync@lists.samba.org]8;;\.

       This  program  uses  the  excellent  zlib compression library written by
       Jean-loup Gailly and Mark Adler.

THANKS
       Special thanks go out to: John Van  Essen,  Matt  McCutchen,  Wesley  W.
       Terpstra, David Dykstra, Jos Backus, Sebastian Krahmer, Martin Pool, and
       our gone-but-not-forgotten compadre, J.W. Schultz.

       Thanks  also to Richard Brent, Brendan Mackay, Bill Waite, Stephen Roth-
       well and David Bell.  I've probably missed some people, my apologies  if
       I have.

AUTHOR
       Rsync  was  originally  written  by  Andrew Tridgell and Paul Mackerras.
       Many people from around the world have helped to  maintain  and  improve
       it.

       Special  thanks  go  to Wayne Davison, who maintained rsync from 2004 to
       2024.

       Mailing  lists  for   support   and   development   are   available   at
       ]8;;https://lists.samba.org/\https://lists.samba.org/]8;;\.

rsync 3.5.0                       16 Sep 2026                          rsync(1)

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