TRS(1) Linux User's Manual TRS(1)
NAME
trs - filter replacing strings
SYNOPSIS
trs [-[r]e] 'REPLACE_THIS WITH_THAT [AND_THIS WITH_THAT]...'
trs [-[r]f] FILE
DESCRIPTION
Copy stdin to stdout replacing every occurrence of given strings with
other ones. This is similar to tr(1), but replaces strings, not only
single chars.
Rules (separated by whitespace) can be given directly after -e option,
or can be read from FILE. Argument not preceded by -e or -f is guessed
to be a script when it contains some whitespace, or a filename other-
wise.
Comments are allowed from # until the end of line. The character # in
strings must be specified as \#.
Standard C-like escapes \a \b \e \f \n \r \t \v \\ \nnn are recognized.
In addition, \s means a space character and \! means an empty string.
Sets of acceptable characters at a given position can be specified be-
tween \[ and ]. ASCII ranges in sets can be shortly written as
FIRST-LAST. When a set consists of only a single range, \[ and \] can
be omitted.
When a part of the string to translate is enclosed in \{...\}, only that
part is replaced. Any text outside \{...\} serves as an assertion: a
string is translated only if it is preceded by the given text and fol-
lowed by another one. \{ at the beginning or \} at the end of the
string can be omitted. Text outside \{...\} is treated as untranslated.
Before the beginning of the file and after its end there are only \n's.
Thus, for example, \n\{.\}\n matches . on a line by itself, including
the first line, and the last one even without the \n marker.
A fragment of the form \?x=N, where x is a letter A-Za-z and N is a
digit 0-9, contained in the target text sets the variable x to the value
N when that rule succeeds. Similar fragment in the source text causes
the given rule to be considered only if that variable has such value.
Initially all variables have the value of 0. Several assignments or
conditions can be present in one rule - they are ANDed together.
OPTIONS
-e Give the translation rules directly in the command line.
-f Get them from the file specified.
-r Reverse every rule. This affects only the next -e or -f option.
Of course this doesn't have to give the reverse translation! Any
rule containing any of \{\}\[\]\{\}\- is taken in only one direc-
tion. You may force any rule to be taken in only one direction by
enclosing the string to translate in \{...\}.
--help display help and exit
--version
output version information and exit
Multiple -e or -f options are allowed. All rules are loaded together
then, and earlier ones have precedence.
EXAMPLE
$ echo Leeloo |trs -e 'el n e i i aqq o\}\n x o u'
Linux
DIFFERENCES FROM sed
The main difference between trs and sed 's///g; ...' (excluding sed's
regular expressions) is that sed takes every rule in the order specified
and applies it to the whole line of translated file, whereas trs exam-
ines every position and tries all rules in this place first. In sed
every next rule is fed with the text produced by the previous one,
whereas in trs every piece of text can be translated at most once (if
more than one rule matches at a given position, the one mentioned ear-
lier wins). That's why sed isn't well suited for translating between
character sets. On the other hand, tr translates only single bytes, so
it can't be used for Unicode conversions, or TeX / SGML ways for speci-
fying extended characters.
Another example:
$ echo 642 |trs -e '4 7 72 66 64 4'
42
$ echo 642 |sed 's/4/7/g; s/72/66/g; s/64/4/g'
666
The string to replace can be empty; there must be something outside \{\}
then. In this special case only one such create-from-nothing rule can
success at a given position. For example, \}\x80\-\xFF @ precedes every
character with high byte set with @. The rule of the form some\{ thing
doesn't work at the end of a file.
SEE ALSO
tr(1), konwert(1)
COPYRIGHT
trs is a filter replacing strings. It forms part of the konwert package.
Copyright (c) 1998 Marcin 'Qrczak' Kowalczyk
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2 of the License, or (at your
option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABIL-
ITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public Li-
cense for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
AUTHOR
__("< Marcin Kowalczyk * qrczak@knm.org.pl http://qrczak.home.ml.org/
\__/ GCS/M d- s+:-- a21 C+++>+++$ UL++>++++$ P+++ L++>++++$ E->++
^^ W++ N+++ o? K? w(---) O? M- V? PS-- PE++ Y? PGP->+ t
QRCZAK 5? X- R tv-- b+>++ DI D- G+ e>++++ h! r--%>++ y-
Konwert 12 Jul 1998 TRS(1)
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