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Add individual documentation pages for string's subcommands

Browse Source 
This adds string-x.rst for each subcommand x of string. The main page
(string.rst) is not changed, except that examples are shown directly after
each subcommand.  The subcommand sections in string.rst are created by
textual inclusion of parts of the string-x.rst files.

Subcommand man pages can be viewed with either of:

```
man string collect
man string-collect
string collect <press F1 or Alt-h>
string collect -h
```

While `string -h ...` still prints the full help.

Closes #5968
This commit is contained in:
Johannes Altmanninger 2019-10-27 10:56:24 +01:00
parent 6050ccbb02
commit 08eac28bd8
19 changed files with 748 additions and 279 deletions
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share/completions/string.fish
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# Completion for builtin string # Completion for builtin string
# This follows a strict command-then-options approach, so we can just test the number of tokens # This follows a strict command-then-options approach, so we can just test the number of tokens
complete -f -c string complete -f -c string
complete -f -c string -n "test (count (commandline -opc)) -le 2" -s h -l help -d "Display help and exit"
complete -f -c string -n "test (count (commandline -opc)) -ge 2; and not contains -- (commandline -opc)[2] escape collect" -s q -l quiet -d "Do not print output" complete -f -c string -n "test (count (commandline -opc)) -ge 2; and not contains -- (commandline -opc)[2] escape collect" -s q -l quiet -d "Do not print output"
complete -f -c string -n "test (count (commandline -opc)) -lt 2" -a "lower" complete -f -c string -n "test (count (commandline -opc)) -lt 2" -a "lower"
complete -f -c string -n "test (count (commandline -opc)) -lt 2" -a "upper" complete -f -c string -n "test (count (commandline -opc)) -lt 2" -a "upper"

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string-collect - join strings into one
======================================
Synopsis
--------
.. BEGIN SYNOPSIS
::
string collect [(-N | --no-trim-newlines)] [STRING...]
.. END SYNOPSIS
Description
-----------
.. BEGIN DESCRIPTION
``string collect`` collects its input into a single output argument, without splitting the output when used in a command substitution. This is useful when trying to collect multiline output from another command into a variable. Exit status: 0 if any output argument is non-empty, or 1 otherwise.
If invoked with multiple arguments instead of input, ``string collect`` preserves each argument separately, where the number of output arguments is equal to the number of arguments given to ``string collect``.
Any trailing newlines on the input are trimmed, just as with ``"$(cmd)"`` substitution in sh. ``--no-trim-newlines`` can be used to disable this behavior, which may be useful when running a command such as ``set contents (cat filename | string collect -N)``.
.. END DESCRIPTION
Examples
--------
.. BEGIN EXAMPLES
::
>_ echo \"(echo one\ntwo\nthree | string collect)\"
"one
two
three
"
>_ echo \"(echo one\ntwo\nthree | string collect -N)\"
"one
two
three"
.. END EXAMPLES

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sphinx_doc_src/cmds/string-escape.rst Normal file
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string-escape - escape special characters
=========================================
Synopsis
--------
.. BEGIN SYNOPSIS
::
string escape [(-n | --no-quoted)] [--style=xxx] [STRING...]
string unescape [--style=xxx] [STRING...]
.. END SYNOPSIS
Description
-----------
.. BEGIN DESCRIPTION
``string escape`` escapes each STRING in one of three ways. The first is ``--style=script``. This is the default. It alters the string such that it can be passed back to ``eval`` to produce the original argument again. By default, all special characters are escaped, and quotes are used to simplify the output when possible. If ``-n`` or ``--no-quoted`` is given, the simplifying quoted format is not used. Exit status: 0 if at least one string was escaped, or 1 otherwise.
``--style=var`` ensures the string can be used as a variable name by hex encoding any non-alphanumeric characters. The string is first converted to UTF-8 before being encoded.
``--style=url`` ensures the string can be used as a URL by hex encoding any character which is not legal in a URL. The string is first converted to UTF-8 before being encoded.
``--style=regex`` escapes an input string for literal matching within a regex expression. The string is first converted to UTF-8 before being encoded.
``string unescape`` performs the inverse of the ``string escape`` command. If the string to be unescaped is not properly formatted it is ignored. For example, doing ``string unescape --style=var (string escape --style=var $str)`` will return the original string. There is no support for unescaping ``--style=regex``.
.. END DESCRIPTION
Examples
--------
.. BEGIN EXAMPLES
::
>_ echo \\x07 | string escape
cg
>_ string escape --style=var 'a1 b2'\\u6161
a1_20b2__c_E6_85_A1
.. END EXAMPLES

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string-join - join strings with delimiter
=========================================
Synopsis
--------
.. BEGIN SYNOPSIS
::
string join [(-q | --quiet)] SEP [STRING...]
string join0 [(-q | --quiet)] [STRING...]
.. END SYNOPSIS
Description
-----------
.. BEGIN DESCRIPTION
``string join`` joins its STRING arguments into a single string separated by SEP, which can be an empty string. Exit status: 0 if at least one join was performed, or 1 otherwise.
``string join0`` joins its STRING arguments into a single string separated by the zero byte (NUL), and adds a trailing NUL. This is most useful in conjunction with tools that accept NUL-delimited input, such as ``sort -z``. Exit status: 0 if at least one join was performed, or 1 otherwise.
.. END DESCRIPTION
Examples
--------
.. BEGIN EXAMPLES
::
>_ seq 3 | string join ...
1...2...3
.. END EXAMPLES

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string-join0 - join strings with zero bytes
===========================================
.. include:: string-join.rst
:start-line: 2

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string-length - print string lengths
====================================
Synopsis
--------
.. BEGIN SYNOPSIS
::
string length [(-q | --quiet)] [STRING...]
.. END SYNOPSIS
Description
-----------
.. BEGIN DESCRIPTION
``string length`` reports the length of each string argument in characters. Exit status: 0 if at least one non-empty STRING was given, or 1 otherwise.
.. END DESCRIPTION
Examples
--------
.. BEGIN EXAMPLES
::
>_ string length 'hello, world'
12
>_ set str foo
>_ string length -q $str; echo $status
0
# Equivalent to test -n $str
.. END EXAMPLES

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string-lower - convert strings to lowercase
===========================================
Synopsis
--------
.. BEGIN SYNOPSIS
::
string lower [(-q | --quiet)] [STRING...]
.. END SYNOPSIS
Description
-----------
.. BEGIN DESCRIPTION
``string lower`` converts each string argument to lowercase. Exit status: 0 if at least one string was converted to lowercase, else 1. This means that in conjunction with the ``-q`` flag you can readily test whether a string is already lowercase.
.. END DESCRIPTION
.. BEGIN EXAMPLES
.. END EXAMPLES

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string-match - match substrings
===============================
Synopsis
--------
.. BEGIN SYNOPSIS
::
string match [(-a | --all)] [(-e | --entire)] [(-i | --ignore-case)] [(-r | --regex)] [(-n | --index)] [(-q | --quiet)] [(-v | --invert)] PATTERN [STRING...]
.. END SYNOPSIS
Description
-----------
.. BEGIN DESCRIPTION
``string match`` tests each STRING against PATTERN and prints matching substrings. Only the first match for each STRING is reported unless ``-a`` or ``--all`` is given, in which case all matches are reported.
If you specify the ``-e`` or ``--entire`` then each matching string is printed including any prefix or suffix not matched by the pattern (equivalent to ``grep`` without the ``-o`` flag). You can, obviously, achieve the same result by prepending and appending ``*`` or ``.*`` depending on whether or not you have specified the ``--regex`` flag. The ``--entire`` flag is simply a way to avoid having to complicate the pattern in that fashion and make the intent of the ``string match`` clearer. Without ``--entire`` and ``--regex``, a PATTERN will need to match the entire STRING before it will be reported.
Matching can be made case-insensitive with ``--ignore-case`` or ``-i``.
If ``--index`` or ``-n`` is given, each match is reported as a 1-based start position and a length. By default, PATTERN is interpreted as a glob pattern matched against each entire STRING argument. A glob pattern is only considered a valid match if it matches the entire STRING.
If ``--regex`` or ``-r`` is given, PATTERN is interpreted as a Perl-compatible regular expression, which does not have to match the entire STRING. For a regular expression containing capturing groups, multiple items will be reported for each match, one for the entire match and one for each capturing group. With this, only the matching part of the STRING will be reported, unless ``--entire`` is given.
If ``--invert`` or ``-v`` is used the selected lines will be only those which do not match the given glob pattern or regular expression.
Exit status: 0 if at least one match was found, or 1 otherwise.
.. END DESCRIPTION
Examples
--------
.. BEGIN EXAMPLES
Match Glob Examples
^^^^^^^^^^^^^^^^^^^
::
>_ string match '?' a
a
>_ string match 'a*b' axxb
axxb
>_ string match -i 'a??B' Axxb
Axxb
>_ echo 'ok?' | string match '*\\?'
ok?
# Note that only the second STRING will match here.
>_ string match 'foo' 'foo1' 'foo' 'foo2'
foo
>_ string match -e 'foo' 'foo1' 'foo' 'foo2'
foo1
foo
foo2
>_ string match 'foo?' 'foo1' 'foo' 'foo2'
foo1
foo
foo2
Match Regex Examples
^^^^^^^^^^^^^^^^^^^^
::
>_ string match -r 'cat|dog|fish' 'nice dog'
dog
>_ string match -r -v "c.*[12]" {cat,dog}(seq 1 4)
dog1
dog2
cat3
dog3
cat4
dog4
>_ string match -r '(\\d\\d?):(\\d\\d):(\\d\\d)' 2:34:56
2:34:56
2
34
56
>_ string match -r '^(\\w{{2,4}})\\g1$' papa mud murmur
papa
pa
murmur
mur
>_ string match -r -a -n at ratatat
2 2
4 2
6 2
>_ string match -r -i '0x[0-9a-f]{{1,8}}' 'int magic = 0xBadC0de;'
0xBadC0de
.. END EXAMPLES

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string-repeat - multiply a string
=================================
Synopsis
--------
.. BEGIN SYNOPSIS
::
string repeat [(-n | --count) COUNT] [(-m | --max) MAX] [(-N | --no-newline)] [(-q | --quiet)] [STRING...]
.. END SYNOPSIS
Description
-----------
.. BEGIN DESCRIPTION
``string repeat`` repeats the STRING ``-n`` or ``--count`` times. The ``-m`` or ``--max`` option will limit the number of outputted char (excluding the newline). This option can be used by itself or in conjunction with ``--count``. If both ``--count`` and ``--max`` are present, max char will be outputed unless the final repeated string size is less than max, in that case, the string will repeat until count has been reached. Both ``--count`` and ``--max`` will accept a number greater than or equal to zero, in the case of zero, nothing will be outputed. If ``-N`` or ``--no-newline`` is given, the output won't contain a newline character at the end. Exit status: 0 if yielded string is not empty, 1 otherwise.
.. END DESCRIPTION
Examples
--------
.. BEGIN EXAMPLES
Repeat Examples
^^^^^^^^^^^^^^^
::
>_ string repeat -n 2 'foo '
foo foo
>_ echo foo | string repeat -n 2
foofoo
>_ string repeat -n 2 -m 5 'foo'
foofo
>_ string repeat -m 5 'foo'
foofo
.. END EXAMPLES

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string-replace - replace substrings
===================================
Synopsis
--------
.. BEGIN SYNOPSIS
::
string replace [(-a | --all)] [(-f | --filter)] [(-i | --ignore-case)] [(-r | --regex)] [(-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``.
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

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string-split - split strings by delimiter
=========================================
Synopsis
--------
.. BEGIN SYNOPSIS
::
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...]
.. END SYNOPSIS
Description
-----------
.. BEGIN DESCRIPTION
``string split`` splits each STRING on the separator SEP, which can be an empty string. If ``-m`` or ``--max`` is specified, at most MAX splits are done on each STRING. If ``-r`` or ``--right`` is given, splitting is performed right-to-left. This is useful in combination with ``-m`` or ``--max``. With ``-n`` or ``--no-empty``, empty results are excluded from consideration (e.g. ``hello\n\nworld`` would expand to two strings and not three). Exit status: 0 if at least one split was performed, or 1 otherwise.
See also ``read --delimiter``.
``string split0`` splits each STRING on the zero byte (NUL). Options are the same as ``string split`` except that no separator is given.
``split0`` has the important property that its output is not further split when used in a command substitution, allowing for the command substitution to produce elements containing newlines. This is most useful when used with Unix tools that produce zero bytes, such as ``find -print0`` or ``sort -z``. See split0 examples below.
.. END DESCRIPTION
Examples
--------
.. BEGIN EXAMPLES
::
>_ string split . example.com
example
com
>_ string split -r -m1 / /usr/local/bin/fish
/usr/local/bin
fish
>_ string split '' abc
a
b
c
NUL Delimited Examples
^^^^^^^^^^^^^^^^^^^^^^
::
>_ # Count files in a directory, without being confused by newlines.
>_ count (find . -print0 | string split0)
42
>_ # Sort a list of elements which may contain newlines
>_ set foo beta alpha\\ngamma
>_ set foo (string join0 $foo | sort -z | string split0)
>_ string escape $foo[1]
alpha\\ngamma
.. END EXAMPLES

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string-split0 - split on zero bytes
===================================
.. include:: string-split.rst
:start-line: 2

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string-sub - extract substrings
===============================
Synopsis
--------
.. BEGIN SYNOPSIS
::
string sub [(-s | --start) START] [(-l | --length) LENGTH] [(-q | --quiet)] [STRING...]
.. END SYNOPSIS
Description
-----------
.. BEGIN DESCRIPTION
``string sub`` prints a substring of each string argument. The start of the substring can be specified with ``-s`` or ``--start`` followed by a 1-based index value. Positive index values are relative to the start of the string and negative index values are relative to the end of the string. The default start value is 1. The length of the substring can be specified with ``-l`` or ``--length``. If the length is not specified, the substring continues to the end of each STRING. Exit status: 0 if at least one substring operation was performed, 1 otherwise.
.. END DESCRIPTION
Examples
--------
.. BEGIN EXAMPLES
::
>_ string sub --length 2 abcde
ab
>_ string sub -s 2 -l 2 abcde
bc
>_ string sub --start=-2 abcde
de
.. END EXAMPLES

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string-trim - remove trailing whitespace
========================================
Synopsis
--------
.. BEGIN SYNOPSIS
::
string trim [(-l | --left)] [(-r | --right)] [(-c | --chars CHARS)] [(-q | --quiet)] [STRING...]
.. END SYNOPSIS
Description
-----------
.. BEGIN DESCRIPTION
``string trim`` removes leading and trailing whitespace from each STRING. If ``-l`` or ``--left`` is given, only leading whitespace is removed. If ``-r`` or ``--right`` is given, only trailing whitespace is trimmed. The ``-c`` or ``--chars`` switch causes the characters in CHARS to be removed instead of whitespace. Exit status: 0 if at least one character was trimmed, or 1 otherwise.
.. END DESCRIPTION
Examples
--------
.. BEGIN EXAMPLES
::
>_ string trim ' abc '
abc
>_ string trim --right --chars=yz xyzzy zany
x
zan
.. END EXAMPLES

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string-unescape - expand escape sequences
=========================================
.. include:: string-escape.rst
:start-line: 2

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string-upper - convert strings to uppercase
===========================================
Synopsis
--------
.. BEGIN SYNOPSIS
::
string upper [(-q | --quiet)] [STRING...]
.. END SYNOPSIS
Description
-----------
.. BEGIN DESCRIPTION
``string upper`` converts each string argument to uppercase. Exit status: 0 if at least one string was converted to uppercase, else 1. This means that in conjunction with the ``-q`` flag you can readily test whether a string is already uppercase.
.. END DESCRIPTION
.. BEGIN EXAMPLES
.. END EXAMPLES

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sphinx_doc_src/cmds/string.rst
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@ -40,140 +40,209 @@ The following subcommands are available.
"collect" subcommand "collect" subcommand
-------------------- --------------------
``string collect [(-N | --no-trim-newlines)] [STRING...]`` .. include:: string-collect.rst
:start-after: BEGIN SYNOPSIS
:end-before: END SYNOPSIS
``string collect`` collects its input into a single output argument, without splitting the output when used in a command substitution. This is useful when trying to collect multiline output from another command into a variable. Exit status: 0 if any output argument is non-empty, or 1 otherwise. .. include:: string-collect.rst
:start-after: BEGIN DESCRIPTION
:end-before: END DESCRIPTION
If invoked with multiple arguments instead of input, ``string collect`` preserves each argument separately, where the number of output arguments is equal to the number of arguments given to ``string collect``. Examples
^^^^^^^^
Any trailing newlines on the input are trimmed, just as with ``"$(cmd)"`` substitution in sh. ``--no-trim-newlines`` can be used to disable this behavior, which may be useful when running a command such as ``set contents (cat filename | string collect -N)``. .. include:: string-collect.rst
:start-after: BEGIN EXAMPLES
:end-before: END EXAMPLES
"escape" and "unescape" subcommands "escape" and "unescape" subcommands
----------------------------------- -----------------------------------
``string escape [(-n | --no-quoted)] [--style=xxx] [STRING...]`` .. include:: string-escape.rst
:start-after: BEGIN SYNOPSIS
:end-before: END SYNOPSIS
``string escape`` escapes each STRING in one of three ways. The first is ``--style=script``. This is the default. It alters the string such that it can be passed back to ``eval`` to produce the original argument again. By default, all special characters are escaped, and quotes are used to simplify the output when possible. If ``-n`` or ``--no-quoted`` is given, the simplifying quoted format is not used. Exit status: 0 if at least one string was escaped, or 1 otherwise. .. include:: string-escape.rst
:start-after: BEGIN DESCRIPTION
:end-before: END DESCRIPTION
``--style=var`` ensures the string can be used as a variable name by hex encoding any non-alphanumeric characters. The string is first converted to UTF-8 before being encoded. Examples
^^^^^^^^
``--style=url`` ensures the string can be used as a URL by hex encoding any character which is not legal in a URL. The string is first converted to UTF-8 before being encoded. .. include:: string-escape.rst
:start-after: BEGIN EXAMPLES
:end-before: END EXAMPLES
``--style=regex`` escapes an input string for literal matching within a regex expression. The string is first converted to UTF-8 before being encoded. "join" and "join0" subcommands
------------------------------
``string unescape [--style=xxx] [STRING...]`` .. include:: string-join.rst
:start-after: BEGIN SYNOPSIS
:end-before: END SYNOPSIS
``string unescape`` performs the inverse of the ``string escape`` command. If the string to be unescaped is not properly formatted it is ignored. For example, doing ``string unescape --style=var (string escape --style=var $str)`` will return the original string. There is no support for unescaping ``--style=regex``. .. include:: string-join.rst
:start-after: BEGIN DESCRIPTION
:end-before: END DESCRIPTION
"join" subcommand Examples
----------------- ^^^^^^^^
``string join [(-q | --quiet)] SEP [STRING...]`` .. include:: string-join.rst
:start-after: BEGIN EXAMPLES
``string join`` joins its STRING arguments into a single string separated by SEP, which can be an empty string. Exit status: 0 if at least one join was performed, or 1 otherwise. :end-before: END EXAMPLES
"join0" subcommand
------------------
``string join0 [(-q | --quiet)] [STRING...]``
``string join`` joins its STRING arguments into a single string separated by the zero byte (NUL), and adds a trailing NUL. This is most useful in conjunction with tools that accept NUL-delimited input, such as ``sort -z``. Exit status: 0 if at least one join was performed, or 1 otherwise.
"length" subcommand "length" subcommand
------------------- -------------------
``string length [(-q | --quiet)] [STRING...]`` .. include:: string-length.rst
:start-after: BEGIN SYNOPSIS
:end-before: END SYNOPSIS
``string length`` reports the length of each string argument in characters. Exit status: 0 if at least one non-empty STRING was given, or 1 otherwise. .. 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 "lower" subcommand
------------------ ------------------
``string lower [(-q | --quiet)] [STRING...]`` .. include:: string-lower.rst
:start-after: BEGIN SYNOPSIS
:end-before: END SYNOPSIS
``string lower`` converts each string argument to lowercase. Exit status: 0 if at least one string was converted to lowercase, else 1. This means that in conjunction with the ``-q`` flag you can readily test whether a string is already lowercase. .. 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 "match" subcommand
------------------ ------------------
``string match [(-a | --all)] [(-e | --entire)] [(-i | --ignore-case)] [(-r | --regex)] [(-n | --index)] [(-q | --quiet)] [(-v | --invert)] PATTERN [STRING...]`` .. include:: string-match.rst
:start-after: BEGIN SYNOPSIS
:end-before: END SYNOPSIS
``string match`` tests each STRING against PATTERN and prints matching substrings. Only the first match for each STRING is reported unless ``-a`` or ``--all`` is given, in which case all matches are reported. .. include:: string-match.rst
:start-after: BEGIN DESCRIPTION
:end-before: END DESCRIPTION
If you specify the ``-e`` or ``--entire`` then each matching string is printed including any prefix or suffix not matched by the pattern (equivalent to ``grep`` without the ``-o`` flag). You can, obviously, achieve the same result by prepending and appending ``*`` or ``.*`` depending on whether or not you have specified the ``--regex`` flag. The ``--entire`` flag is simply a way to avoid having to complicate the pattern in that fashion and make the intent of the ``string match`` clearer. Without ``--entire`` and ``--regex``, a PATTERN will need to match the entire STRING before it will be reported. .. include:: string-match.rst
:start-after: BEGIN EXAMPLES
Matching can be made case-insensitive with ``--ignore-case`` or ``-i``. :end-before: END EXAMPLES
If ``--index`` or ``-n`` is given, each match is reported as a 1-based start position and a length. By default, PATTERN is interpreted as a glob pattern matched against each entire STRING argument. A glob pattern is only considered a valid match if it matches the entire STRING.
If ``--regex`` or ``-r`` is given, PATTERN is interpreted as a Perl-compatible regular expression, which does not have to match the entire STRING. For a regular expression containing capturing groups, multiple items will be reported for each match, one for the entire match and one for each capturing group. With this, only the matching part of the STRING will be reported, unless ``--entire`` is given.
If ``--invert`` or ``-v`` is used the selected lines will be only those which do not match the given glob pattern or regular expression.
Exit status: 0 if at least one match was found, or 1 otherwise.
"repeat" subcommand "repeat" subcommand
------------------- -------------------
``string repeat [(-n | --count) COUNT] [(-m | --max) MAX] [(-N | --no-newline)] [(-q | --quiet)] [STRING...]`` .. include:: string-repeat.rst
:start-after: BEGIN SYNOPSIS
:end-before: END SYNOPSIS
``string repeat`` repeats the STRING ``-n`` or ``--count`` times. The ``-m`` or ``--max`` option will limit the number of outputted char (excluding the newline). This option can be used by itself or in conjunction with ``--count``. If both ``--count`` and ``--max`` are present, max char will be outputed unless the final repeated string size is less than max, in that case, the string will repeat until count has been reached. Both ``--count`` and ``--max`` will accept a number greater than or equal to zero, in the case of zero, nothing will be outputed. If ``-N`` or ``--no-newline`` is given, the output won't contain a newline character at the end. Exit status: 0 if yielded string is not empty, 1 otherwise. .. 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 "replace" subcommand
-------------------- --------------------
``string replace [(-a | --all)] [(-f | --filter)] [(-i | --ignore-case)] [(-r | --regex)] [(-q | --quiet)] PATTERN REPLACEMENT [STRING...]`` .. include:: string-replace.rst
:start-after: BEGIN SYNOPSIS
:end-before: END SYNOPSIS
``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. .. include:: string-replace.rst
:start-after: BEGIN DESCRIPTION
:end-before: END DESCRIPTION
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}``. .. include:: string-replace.rst
:start-after: BEGIN EXAMPLES
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``. :end-before: END EXAMPLES
Exit status: 0 if at least one replacement was performed, or 1 otherwise.
.. _cmd-string-split: .. _cmd-string-split:
"split" subcommand
------------------
``string split [(-m | --max) MAX] [(-n | --no-empty)] [(-q | --quiet)] [(-r | --right)] SEP [STRING...]``
``string split`` splits each STRING on the separator SEP, which can be an empty string. If ``-m`` or ``--max`` is specified, at most MAX splits are done on each STRING. If ``-r`` or ``--right`` is given, splitting is performed right-to-left. This is useful in combination with ``-m`` or ``--max``. With ``-n`` or ``--no-empty``, empty results are excluded from consideration (e.g. ``hello\n\nworld`` would expand to two strings and not three). Exit status: 0 if at least one split was performed, or 1 otherwise.
See also ``read --delimiter``.
.. _cmd-string-split0: .. _cmd-string-split0:
"split0" subcommand "split" and "split0" subcommands
------------------- --------------------------------
``string split0 [(-m | --max) MAX] [(-n | --no-empty)] [(-q | --quiet)] [(-r | --right)] [STRING...]`` .. include:: string-split.rst
:start-after: BEGIN SYNOPSIS
:end-before: END SYNOPSIS
``string split0`` splits each STRING on the zero byte (NUL). Options are the same as ``string split`` except that no separator is given. .. include:: string-split.rst
:start-after: BEGIN DESCRIPTION
:end-before: END DESCRIPTION
``split0`` has the important property that its output is not further split when used in a command substitution, allowing for the command substitution to produce elements containing newlines. This is most useful when used with Unix tools that produce zero bytes, such as ``find -print0`` or ``sort -z``. See split0 examples below. Examples
^^^^^^^^
.. include:: string-split.rst
:start-after: BEGIN EXAMPLES
:end-before: END EXAMPLES
"sub" subcommand "sub" subcommand
---------------- ----------------
``string sub [(-s | --start) START] [(-l | --length) LENGTH] [(-q | --quiet)] [STRING...]`` .. include:: string-sub.rst
:start-after: BEGIN SYNOPSIS
:end-before: END SYNOPSIS
``string sub`` prints a substring of each string argument. The start of the substring can be specified with ``-s`` or ``--start`` followed by a 1-based index value. Positive index values are relative to the start of the string and negative index values are relative to the end of the string. The default start value is 1. The length of the substring can be specified with ``-l`` or ``--length``. If the length is not specified, the substring continues to the end of each STRING. Exit status: 0 if at least one substring operation was performed, 1 otherwise. .. 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 "trim" subcommand
----------------- -----------------
``string trim [(-l | --left)] [(-r | --right)] [(-c | --chars CHARS)] [(-q | --quiet)] [STRING...]`` .. include:: string-trim.rst
:start-after: BEGIN SYNOPSIS
:end-before: END SYNOPSIS
``string trim`` removes leading and trailing whitespace from each STRING. If ``-l`` or ``--left`` is given, only leading whitespace is removed. If ``-r`` or ``--right`` is given, only trailing whitespace is trimmed. The ``-c`` or ``--chars`` switch causes the characters in CHARS to be removed instead of whitespace. Exit status: 0 if at least one character was trimmed, or 1 otherwise. .. 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 "upper" subcommand
------------------ ------------------
``string upper [(-q | --quiet)] [STRING...]`` .. include:: string-upper.rst
:start-after: BEGIN SYNOPSIS
:end-before: END SYNOPSIS
``string upper`` converts each string argument to uppercase. Exit status: 0 if at least one string was converted to uppercase, else 1. This means that in conjunction with the ``-q`` flag you can readily test whether a string is already uppercase. .. 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 Regular Expressions
------------------- -------------------
@ -239,215 +308,8 @@ If you are familiar with these, it is useful to know how ``string`` differs from
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 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, whie `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). 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``. 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``. ``string split somedelimiter`` is a replacement for ``tr somedelimiter \\n``.
Examples
--------
::
>_ string length 'hello, world'
12
>_ set str foo
>_ string length -q $str; echo $status
0
# Equivalent to test -n $str
::
>_ string sub --length 2 abcde
ab
>_ string sub -s 2 -l 2 abcde
bc
>_ string sub --start=-2 abcde
de
::
>_ string split . example.com
example
com
>_ string split -r -m1 / /usr/local/bin/fish
/usr/local/bin
fish
>_ string split '' abc
a
b
c
::
>_ seq 3 | string join ...
1...2...3
::
>_ string trim ' abc '
abc
>_ string trim --right --chars=yz xyzzy zany
x
zan
::
>_ echo \\x07 | string escape
cg
::
>_ string escape --style=var 'a1 b2'\\u6161
a1_20b2__c_E6_85_A1
::
>_ echo \"(echo one\ntwo\nthree | string collect)\"
"one
two
three
"
>_ echo \"(echo one\ntwo\nthree | string collect -N)\"
"one
two
three"
Match Glob Examples
-------------------
::
>_ string match '?' a
a
>_ string match 'a*b' axxb
axxb
>_ string match -i 'a??B' Axxb
Axxb
>_ echo 'ok?' | string match '*\\?'
ok?
# Note that only the second STRING will match here.
>_ string match 'foo' 'foo1' 'foo' 'foo2'
foo
>_ string match -e 'foo' 'foo1' 'foo' 'foo2'
foo1
foo
foo2
>_ string match 'foo?' 'foo1' 'foo' 'foo2'
foo1
foo
foo2
Match Regex Examples
--------------------
::
>_ string match -r 'cat|dog|fish' 'nice dog'
dog
>_ string match -r -v "c.*[12]" {cat,dog}(seq 1 4)
dog1
dog2
cat3
dog3
cat4
dog4
>_ string match -r '(\\d\\d?):(\\d\\d):(\\d\\d)' 2:34:56
2:34:56
2
34
56
>_ string match -r '^(\\w{{2,4}})\\g1$' papa mud murmur
papa
pa
murmur
mur
>_ string match -r -a -n at ratatat
2 2
4 2
6 2
>_ string match -r -i '0x[0-9a-f]{{1,8}}' 'int magic = 0xBadC0de;'
0xBadC0de
NUL Delimited Examples
----------------------
::
>_ # Count files in a directory, without being confused by newlines.
>_ count (find . -print0 | string split0)
42
>_ # Sort a list of elements which may contain newlines
>_ set foo beta alpha\\ngamma
>_ set foo (string join0 $foo | sort -z | string split0)
>_ string escape $foo[1]
alpha\\ngamma
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
Repeat Examples
---------------
::
>_ string repeat -n 2 'foo '
foo foo
>_ echo foo | string repeat -n 2
foofoo
>_ string repeat -n 2 -m 5 'foo'
foofo
>_ string repeat -m 5 'foo'
foofo

2
sphinx_doc_src/index.rst
View File

@ -730,7 +730,7 @@ Command substitution
The output of a series of commands can be used as the parameters to another command. If a parameter contains a set of parenthesis, the text enclosed by the parenthesis will be interpreted as a list of commands. On expansion, this list is executed, and substituted by the output. If the output is more than one line long, each line will be expanded to a new parameter. Setting ``IFS`` to the empty string will disable line splitting. The output of a series of commands can be used as the parameters to another command. If a parameter contains a set of parenthesis, the text enclosed by the parenthesis will be interpreted as a list of commands. On expansion, this list is executed, and substituted by the output. If the output is more than one line long, each line will be expanded to a new parameter. Setting ``IFS`` to the empty string will disable line splitting.
If the output is piped to :ref:`string split <cmd-string-split>` or `string split0 <cmd-string-split0>` as the last step, those splits are used as they appear and no additional splitting on newlines takes place. If the output is piped to :ref:`string split or string split0 <cmd-string-split>` as the last step, those splits are used as they appear and no additional splitting on newlines takes place.
The exit status of the last run command substitution is available in the `status <#variables-status>`_ variable if the substitution occurs in the context of a ``set`` command. The exit status of the last run command substitution is available in the `status <#variables-status>`_ variable if the substitution occurs in the context of a ``set`` command.

5
src/builtin_string.cpp
View File

@ -1366,6 +1366,11 @@ int builtin_string(parser_t &parser, io_streams_t &streams, wchar_t **argv) {
return STATUS_INVALID_ARGS; return STATUS_INVALID_ARGS;
} }
if (argc >= 3 && (std::wcscmp(argv[2], L"-h") == 0 || std::wcscmp(argv[2], L"--help") == 0)) {
wcstring string_dash_subcommand = wcstring(argv[0]) + L"-" + argv[1];
builtin_print_help(parser, streams, string_dash_subcommand.c_str());
return STATUS_CMD_OK;
}
argc--; argc--;
argv++; argv++;
return subcmd->handler(parser, streams, argc, argv); return subcmd->handler(parser, streams, argc, argv);