mirror of
https://github.com/fish-shell/fish-shell.git
synced 2024-11-30 14:24:35 +08:00
316 lines
9.4 KiB
ReStructuredText
316 lines
9.4 KiB
ReStructuredText
.. _cmd-string:
|
|
|
|
string - manipulate strings
|
|
===========================
|
|
|
|
Synopsis
|
|
--------
|
|
|
|
::
|
|
|
|
string collect [(-N | --no-trim-newlines)] [STRING...]
|
|
string escape [(-n | --no-quoted)] [--style=xxx] [STRING...]
|
|
string join [(-q | --quiet)] SEP [STRING...]
|
|
string join0 [(-q | --quiet)] [STRING...]
|
|
string length [(-q | --quiet)] [STRING...]
|
|
string lower [(-q | --quiet)] [STRING...]
|
|
string match [(-a | --all)] [(-e | --entire)] [(-i | --ignore-case)] [(-r | --regex)] [(-n | --index)] [(-q | --quiet)] [(-v | --invert)] PATTERN [STRING...]
|
|
string repeat [(-n | --count) COUNT] [(-m | --max) MAX] [(-N | --no-newline)] [(-q | --quiet)] [STRING...]
|
|
string replace [(-a | --all)] [(-f | --filter)] [(-i | --ignore-case)] [(-r | --regex)] [(-q | --quiet)] PATTERN REPLACEMENT [STRING...]
|
|
string split [(-m | --max) MAX] [(-n | --no-empty)] [(-q | --quiet)] [(-r | --right)] SEP [STRING...]
|
|
string split0 [(-m | --max) MAX] [(-n | --no-empty)] [(-q | --quiet)] [(-r | --right)] [STRING...]
|
|
string sub [(-s | --start) START] [(-l | --length) LENGTH] [(-q | --quiet)] [STRING...]
|
|
string trim [(-l | --left)] [(-r | --right)] [(-c | --chars CHARS)] [(-q | --quiet)] [STRING...]
|
|
string unescape [--style=xxx] [STRING...]
|
|
string upper [(-q | --quiet)] [STRING...]
|
|
|
|
Description
|
|
-----------
|
|
|
|
``string`` performs operations on strings.
|
|
|
|
STRING arguments are taken from the command line unless standard input is connected to a pipe or a file, in which case they are read from standard input, one STRING per line. It is an error to supply STRING arguments on the command line and on standard input.
|
|
|
|
Arguments beginning with ``-`` are normally interpreted as switches; ``--`` causes the following arguments not to be treated as switches even if they begin with ``-``. Switches and required arguments are recognized only on the command line.
|
|
|
|
Most subcommands accept a ``-q`` or ``--quiet`` switch, which suppresses the usual output but exits with the documented status.
|
|
|
|
The following subcommands are available.
|
|
|
|
"collect" subcommand
|
|
--------------------
|
|
|
|
.. include:: string-collect.rst
|
|
:start-after: BEGIN SYNOPSIS
|
|
:end-before: END SYNOPSIS
|
|
|
|
.. include:: string-collect.rst
|
|
:start-after: BEGIN DESCRIPTION
|
|
:end-before: END DESCRIPTION
|
|
|
|
Examples
|
|
^^^^^^^^
|
|
|
|
.. include:: string-collect.rst
|
|
:start-after: BEGIN EXAMPLES
|
|
:end-before: END EXAMPLES
|
|
|
|
"escape" and "unescape" subcommands
|
|
-----------------------------------
|
|
|
|
.. include:: string-escape.rst
|
|
:start-after: BEGIN SYNOPSIS
|
|
:end-before: END SYNOPSIS
|
|
|
|
.. include:: string-escape.rst
|
|
:start-after: BEGIN DESCRIPTION
|
|
:end-before: END DESCRIPTION
|
|
|
|
Examples
|
|
^^^^^^^^
|
|
|
|
.. include:: string-escape.rst
|
|
:start-after: BEGIN EXAMPLES
|
|
:end-before: END EXAMPLES
|
|
|
|
"join" and "join0" subcommands
|
|
------------------------------
|
|
|
|
.. include:: string-join.rst
|
|
:start-after: BEGIN SYNOPSIS
|
|
:end-before: END SYNOPSIS
|
|
|
|
.. include:: string-join.rst
|
|
:start-after: BEGIN DESCRIPTION
|
|
:end-before: END DESCRIPTION
|
|
|
|
Examples
|
|
^^^^^^^^
|
|
|
|
.. include:: string-join.rst
|
|
:start-after: BEGIN EXAMPLES
|
|
:end-before: END EXAMPLES
|
|
|
|
"length" subcommand
|
|
-------------------
|
|
|
|
.. include:: string-length.rst
|
|
:start-after: BEGIN SYNOPSIS
|
|
:end-before: END SYNOPSIS
|
|
|
|
.. include:: string-length.rst
|
|
:start-after: BEGIN DESCRIPTION
|
|
:end-before: END DESCRIPTION
|
|
|
|
Examples
|
|
^^^^^^^^
|
|
|
|
.. include:: string-length.rst
|
|
:start-after: BEGIN EXAMPLES
|
|
:end-before: END EXAMPLES
|
|
|
|
"lower" subcommand
|
|
------------------
|
|
|
|
.. include:: string-lower.rst
|
|
:start-after: BEGIN SYNOPSIS
|
|
:end-before: END SYNOPSIS
|
|
|
|
.. include:: string-lower.rst
|
|
:start-after: BEGIN DESCRIPTION
|
|
:end-before: END DESCRIPTION
|
|
|
|
.. include:: string-lower.rst
|
|
:start-after: BEGIN EXAMPLES
|
|
:end-before: END EXAMPLES
|
|
|
|
"match" subcommand
|
|
------------------
|
|
|
|
.. include:: string-match.rst
|
|
:start-after: BEGIN SYNOPSIS
|
|
:end-before: END SYNOPSIS
|
|
|
|
.. include:: string-match.rst
|
|
:start-after: BEGIN DESCRIPTION
|
|
:end-before: END DESCRIPTION
|
|
|
|
.. include:: string-match.rst
|
|
:start-after: BEGIN EXAMPLES
|
|
:end-before: END EXAMPLES
|
|
|
|
"repeat" subcommand
|
|
-------------------
|
|
|
|
.. include:: string-repeat.rst
|
|
:start-after: BEGIN SYNOPSIS
|
|
:end-before: END SYNOPSIS
|
|
|
|
.. include:: string-repeat.rst
|
|
:start-after: BEGIN DESCRIPTION
|
|
:end-before: END DESCRIPTION
|
|
|
|
Examples
|
|
^^^^^^^^
|
|
|
|
.. include:: string-repeat.rst
|
|
:start-after: BEGIN EXAMPLES
|
|
:end-before: END EXAMPLES
|
|
|
|
"replace" subcommand
|
|
--------------------
|
|
|
|
.. include:: string-replace.rst
|
|
:start-after: BEGIN SYNOPSIS
|
|
:end-before: END SYNOPSIS
|
|
|
|
.. include:: string-replace.rst
|
|
:start-after: BEGIN DESCRIPTION
|
|
:end-before: END DESCRIPTION
|
|
|
|
.. include:: string-replace.rst
|
|
:start-after: BEGIN EXAMPLES
|
|
:end-before: END EXAMPLES
|
|
|
|
.. _cmd-string-split:
|
|
.. _cmd-string-split0:
|
|
|
|
"split" and "split0" subcommands
|
|
--------------------------------
|
|
|
|
.. include:: string-split.rst
|
|
:start-after: BEGIN SYNOPSIS
|
|
:end-before: END SYNOPSIS
|
|
|
|
.. include:: string-split.rst
|
|
:start-after: BEGIN DESCRIPTION
|
|
:end-before: END DESCRIPTION
|
|
|
|
Examples
|
|
^^^^^^^^
|
|
|
|
.. include:: string-split.rst
|
|
:start-after: BEGIN EXAMPLES
|
|
:end-before: END EXAMPLES
|
|
|
|
"sub" subcommand
|
|
----------------
|
|
|
|
.. include:: string-sub.rst
|
|
:start-after: BEGIN SYNOPSIS
|
|
:end-before: END SYNOPSIS
|
|
|
|
.. include:: string-sub.rst
|
|
:start-after: BEGIN DESCRIPTION
|
|
:end-before: END DESCRIPTION
|
|
|
|
Examples
|
|
^^^^^^^^
|
|
|
|
.. include:: string-sub.rst
|
|
:start-after: BEGIN EXAMPLES
|
|
:end-before: END EXAMPLES
|
|
|
|
"trim" subcommand
|
|
-----------------
|
|
|
|
.. include:: string-trim.rst
|
|
:start-after: BEGIN SYNOPSIS
|
|
:end-before: END SYNOPSIS
|
|
|
|
.. include:: string-trim.rst
|
|
:start-after: BEGIN DESCRIPTION
|
|
:end-before: END DESCRIPTION
|
|
|
|
Examples
|
|
^^^^^^^^
|
|
|
|
.. include:: string-trim.rst
|
|
:start-after: BEGIN EXAMPLES
|
|
:end-before: END EXAMPLES
|
|
|
|
"upper" subcommand
|
|
------------------
|
|
|
|
.. include:: string-upper.rst
|
|
:start-after: BEGIN SYNOPSIS
|
|
:end-before: END SYNOPSIS
|
|
|
|
.. include:: string-upper.rst
|
|
:start-after: BEGIN DESCRIPTION
|
|
:end-before: END DESCRIPTION
|
|
|
|
.. include:: string-upper.rst
|
|
:start-after: BEGIN EXAMPLES
|
|
:end-before: END EXAMPLES
|
|
|
|
Regular Expressions
|
|
-------------------
|
|
|
|
Both the ``match`` and ``replace`` subcommand support regular expressions when used with the ``-r`` or ``--regex`` option. The dialect is that of PCRE2.
|
|
|
|
In general, special characters are special by default, so ``a+`` matches one or more "a"s, while ``a\+`` matches an "a" and then a "+". ``(a+)`` matches one or more "a"s in a capturing group (``(?:XXXX)`` denotes a non-capturing group). For the replacement parameter of ``replace``, ``$n`` refers to the n-th group of the match. In the match parameter, ``\n`` (e.g. ``\1``) refers back to groups.
|
|
|
|
Some features include repetitions:
|
|
|
|
- ``*`` refers to 0 or more repetitions of the previous expression
|
|
- ``+`` 1 or more
|
|
- ``?`` 0 or 1.
|
|
- ``{n}`` to exactly n (where n is a number)
|
|
- ``{n,m}`` at least n, no more than m.
|
|
- ``{n,}`` n or more
|
|
|
|
Character classes, some of the more important:
|
|
|
|
- ``.`` any character except newline
|
|
- ``\d`` a decimal digit and ``\D``, not a decimal digit
|
|
- ``\s`` whitespace and ``\S``, not whitespace
|
|
- ``\w`` a "word" character and ``\W``, a "non-word" character
|
|
- ``[...]`` (where "..." is some characters) is a character set
|
|
- ``[^...]`` is the inverse of the given character set
|
|
- ``[x-y]`` is the range of characters from x-y
|
|
- ``[[:xxx:]]`` is a named character set
|
|
- ``[[:^xxx:]]`` is the inverse of a named character set
|
|
- ``[[:alnum:]]`` : "alphanumeric"
|
|
- ``[[:alpha:]]`` : "alphabetic"
|
|
- ``[[:ascii:]]`` : "0-127"
|
|
- ``[[:blank:]]`` : "space or tab"
|
|
- ``[[:cntrl:]]`` : "control character"
|
|
- ``[[:digit:]]`` : "decimal digit"
|
|
- ``[[:graph:]]`` : "printing, excluding space"
|
|
- ``[[:lower:]]`` : "lower case letter"
|
|
- ``[[:print:]]`` : "printing, including space"
|
|
- ``[[:punct:]]`` : "printing, excluding alphanumeric"
|
|
- ``[[:space:]]`` : "white space"
|
|
- ``[[:upper:]]`` : "upper case letter"
|
|
- ``[[:word:]]`` : "same as \w"
|
|
- ``[[:xdigit:]]`` : "hexadecimal digit"
|
|
|
|
Groups:
|
|
|
|
- ``(...)`` is a capturing group
|
|
- ``(?:...)`` is a non-capturing group
|
|
- ``\n`` is a backreference (where n is the number of the group, starting with 1)
|
|
- ``$n`` is a reference from the replacement expression to a group in the match expression.
|
|
|
|
And some other things:
|
|
|
|
- ``\b`` denotes a word boundary, ``\B`` is not a word boundary.
|
|
- ``^`` is the start of the string or line, ``$`` the end.
|
|
- ``|`` is "alternation", i.e. the "or".
|
|
|
|
Comparison to other tools
|
|
-------------------------
|
|
|
|
Most operations ``string`` supports can also be done by external tools. Some of these include ``grep``, ``sed`` and ``cut``.
|
|
|
|
If you are familiar with these, it is useful to know how ``string`` differs from them.
|
|
|
|
In contrast to these classics, ``string`` reads input either from stdin or as arguments. ``string`` also does not deal with files, so it requires redirections to be used with them.
|
|
|
|
In contrast to ``grep``, ``string``\ s `match` defaults to glob-mode, while `replace` defaults to literal matching. If set to regex-mode, they use PCRE regular expressions, which is comparable to ``grep``\ s `-P` option. `match` defaults to printing just the match, which is like ``grep`` with `-o` (use `--entire` to enable grep-like behavior).
|
|
|
|
Like ``sed``\ s `s/` command, ``string replace`` still prints strings that don't match. ``sed``\ s `-n` in combination with a `/p` modifier or command is like ``string replace -f``.
|
|
|
|
``string split somedelimiter`` is a replacement for ``tr somedelimiter \\n``.
|