File::Basename(3perl) Perl Programmers Reference Guide File::Basename(3perl)
NAME
File::Basename - Parse file paths into directory, filename and suffix.
SYNOPSIS
use File::Basename;
my ($name, $path, $suffix) = fileparse($fullname, @suffixlist);
my $name = fileparse($fullname, @suffixlist);
my $basename = basename($fullname, @suffixlist);
my $dirname = dirname($fullname);
DESCRIPTION
These routines allow you to parse file paths into their directory,
filename and suffix.
NOTE: dirname() and basename() emulate the behaviours, and quirks, of
the shell and C functions of the same name. See each function's
documentation for details. If your concern is just parsing paths it is
safer to use File::Spec's splitpath() and splitdir() methods.
It is guaranteed that
# Where $path_separator is / for Unix, \ for Windows, etc...
dirname($path) . $path_separator . basename($path);
is equivalent to the original path for all systems but VMS.
"fileparse"
my($filename, $dirs, $suffix) = fileparse($path);
my($filename, $dirs, $suffix) = fileparse($path, @suffixes);
my $filename = fileparse($path, @suffixes);
The fileparse() routine divides a file path into its $dirs,
$filename and (optionally) the filename $suffix.
$dirs contains everything up to and including the last directory
separator in the $path including the volume (if applicable). The
remainder of the $path is the $filename.
# On Unix returns ("baz", "/foo/bar/", "")
fileparse("/foo/bar/baz");
# On Windows returns ("baz", 'C:\foo\bar\', "")
fileparse('C:\foo\bar\baz');
# On Unix returns ("", "/foo/bar/baz/", "")
fileparse("/foo/bar/baz/");
If @suffixes are given each element is a pattern (either a string or
a "qr//") matched against the end of the $filename. The matching
portion is removed and becomes the $suffix.
# On Unix returns ("baz", "/foo/bar/", ".txt")
fileparse("/foo/bar/baz.txt", qr/\.[^.]*/);
If type is non-Unix (see "fileparse_set_fstype") then the pattern
matching for suffix removal is performed case-insensitively, since
those systems are not case-sensitive when opening existing files.
You are guaranteed that "$dirs . $filename . $suffix" will denote
the same location as the original $path.
"basename"
my $filename = basename($path);
my $filename = basename($path, @suffixes);
This function is provided for compatibility with the Unix shell
command basename(1). It does NOT always return the file name
portion of a path as you might expect. To be safe, if you want the
file name portion of a path use fileparse().
basename() returns the last level of a filepath even if the last
level is clearly directory. In effect, it is acting like pop() for
paths. This differs from fileparse()'s behaviour.
# Both return "bar"
basename("/foo/bar");
basename("/foo/bar/");
@suffixes work as in fileparse() except all regex metacharacters are
quoted.
# These two function calls are equivalent.
my $filename = basename("/foo/bar/baz.txt", ".txt");
my $filename = fileparse("/foo/bar/baz.txt", qr/\Q.txt\E/);
Also note that in order to be compatible with the shell command,
basename() does not strip off a suffix if it is identical to the
remaining characters in the filename.
"dirname"
This function is provided for compatibility with the Unix shell
command dirname(1) and has inherited some of its quirks. In spite
of its name it does NOT always return the directory name as you
might expect. To be safe, if you want the directory name of a path
use fileparse().
Only on VMS (where there is no ambiguity between the file and
directory portions of a path) and AmigaOS (possibly due to an
implementation quirk in this module) does dirname() work like
fileparse($path), returning just the $dirs.
# On VMS and AmigaOS
my $dirs = dirname($path);
When using Unix or MSDOS syntax this emulates the dirname(1) shell
function which is subtly different from how fileparse() works. It
returns all but the last level of a file path even if the last level
is clearly a directory. In effect, it is not returning the
directory portion but simply the path one level up acting like
chop() for file paths.
Also unlike fileparse(), dirname() does not include a trailing slash
on its returned path.
# returns /foo/bar. fileparse() would return /foo/bar/
dirname("/foo/bar/baz");
# also returns /foo/bar despite the fact that baz is clearly a
# directory. fileparse() would return /foo/bar/baz/
dirname("/foo/bar/baz/");
# returns '.'. fileparse() would return 'foo/'
dirname("foo/");
Under VMS, if there is no directory information in the $path, then
the current default device and directory is used.
"fileparse_set_fstype"
my $type = fileparse_set_fstype();
my $previous_type = fileparse_set_fstype($type);
Normally File::Basename will assume a file path type native to your
current operating system (ie. /foo/bar style on Unix, \foo\bar on
Windows, etc...). With this function you can override that
assumption.
Valid $types are "MacOS", "VMS", "AmigaOS", "OS2", "RISCOS",
"MSWin32", "DOS" (also "MSDOS" for backwards bug compatibility),
"Epoc" and "Unix" (all case-insensitive). If an unrecognized $type
is given "Unix" will be assumed.
If you've selected VMS syntax, and the file specification you pass
to one of these routines contains a "/", they assume you are using
Unix emulation and apply the Unix syntax rules instead, for that
function call only.
SEE ALSO
dirname(1), basename(1), File::Spec
perl v5.40.1 2026-08-30 File::Basename(3perl)
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