fish-shell/doc_src/cmds/string-replace.rst
2024-07-23 11:47:58 +02:00

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string-replace - replace substrings
===================================
Synopsis
--------
.. BEGIN SYNOPSIS
.. synopsis::
string replace [-a | --all] [-f | --filter] [-i | --ignore-case]
[-r | --regex] [(-m | --max-matches) MAX] [-q | --quiet]
PATTERN REPLACEMENT [STRING ...]
.. END SYNOPSIS
Description
-----------
.. BEGIN DESCRIPTION
``string replace`` is similar to ``string match`` but replaces non-overlapping matching substrings with a replacement string and prints the result. By default, *PATTERN* is treated as a literal substring to be matched.
If **-r** or **--regex** is given, *PATTERN* is interpreted as a Perl-compatible regular expression, and *REPLACEMENT* can contain C-style escape sequences like **\t** as well as references to capturing groups by number or name as *$n* or *${n}*.
If you specify the **-f** or **--filter** flag then each input string is printed only if a replacement was done. This is useful where you would otherwise use this idiom: ``a_cmd | string match pattern | string replace pattern new_pattern``. You can instead just write ``a_cmd | string replace --filter pattern new_pattern``.
If **--max-matches MAX** or **-m MAX** is used, ``string replace`` will stop all processing after MAX lines of input have matched the specified pattern. In the event of ``--filter`` or ``-f``, this means the output will be MAX lines in length. This can be used as an "early exit" optimization when processing long inputs but expecting a limited and fixed number of outputs that might be found considerably before the input stream has been exhausted.
Exit status: 0 if at least one replacement was performed, or 1 otherwise.
.. END DESCRIPTION
Examples
--------
.. BEGIN EXAMPLES
Replace Literal Examples
^^^^^^^^^^^^^^^^^^^^^^^^
::
>_ string replace is was 'blue is my favorite'
blue was my favorite
>_ string replace 3rd last 1st 2nd 3rd
1st
2nd
last
>_ string replace -a ' ' _ 'spaces to underscores'
spaces_to_underscores
Replace Regex Examples
^^^^^^^^^^^^^^^^^^^^^^
::
>_ string replace -r -a '[^\d.]+' ' ' '0 one two 3.14 four 5x'
0 3.14 5
>_ string replace -r '(\w+)\s+(\w+)' '$2 $1 $$' 'left right'
right left $
>_ string replace -r '\s*newline\s*' '\n' 'put a newline here'
put a
here
.. END EXAMPLES