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Diffstat (limited to 'Help/command/string.rst')
| -rw-r--r-- | Help/command/string.rst | 356 |
1 files changed, 224 insertions, 132 deletions
diff --git a/Help/command/string.rst b/Help/command/string.rst index 4f0c45c29..81a206112 100644 --- a/Help/command/string.rst +++ b/Help/command/string.rst @@ -1,81 +1,120 @@ string ------ -.. only:: html - - .. contents:: - String operations. +Synopsis +^^^^^^^^ + +.. parsed-literal:: + + `Search and Replace`_ + string(`FIND`_ <string> <substring> <out-var> [...]) + string(`REPLACE`_ <match-string> <replace-string> <out-var> <input>...) + + `Regular Expressions`_ + string(`REGEX MATCH`_ <match-regex> <out-var> <input>...) + string(`REGEX MATCHALL`_ <match-regex> <out-var> <input>...) + string(`REGEX REPLACE`_ <match-regex> <replace-expr> <out-var> <input>...) + + `Manipulation`_ + string(`APPEND`_ <string-var> [<input>...]) + string(`PREPEND`_ <string-var> [<input>...]) + string(`CONCAT`_ <out-var> [<input>...]) + string(`JOIN`_ <glue> <out-var> [<input>...]) + string(`TOLOWER`_ <string> <out-var>) + string(`TOUPPER`_ <string> <out-var>) + string(`LENGTH`_ <string> <out-var>) + string(`SUBSTRING`_ <string> <begin> <length> <out-var>) + string(`STRIP`_ <string> <out-var>) + string(`GENEX_STRIP`_ <string> <out-var>) + string(`REPEAT`_ <string> <count> <out-var>) + + `Comparison`_ + string(`COMPARE`_ <op> <string1> <string2> <out-var>) + + `Hashing`_ + string(`\<HASH\> <HASH_>`_ <out-var> <input>) + + `Generation`_ + string(`ASCII`_ <number>... <out-var>) + string(`CONFIGURE`_ <string> <out-var> [...]) + string(`MAKE_C_IDENTIFIER`_ <string> <out-var>) + string(`RANDOM`_ [<option>...] <out-var>) + string(`TIMESTAMP`_ <out-var> [<format string>] [UTC]) + string(`UUID`_ <out-var> ...) + Search and Replace ^^^^^^^^^^^^^^^^^^ -FIND -"""" +.. _FIND: -:: +.. code-block:: cmake - string(FIND <string> <substring> <output variable> [REVERSE]) + string(FIND <string> <substring> <output_variable> [REVERSE]) -Return the position where the given substring was found in -the supplied string. If the ``REVERSE`` flag was used, the command will +Return the position where the given ``<substring>`` was found in +the supplied ``<string>``. If the ``REVERSE`` flag was used, the command will search for the position of the last occurrence of the specified -substring. If the substring is not found, a position of -1 is returned. +``<substring>``. If the ``<substring>`` is not found, a position of -1 is +returned. -REPLACE -""""""" +The ``string(FIND)`` subcommand treats all strings as ASCII-only characters. +The index stored in ``<output_variable>`` will also be counted in bytes, +so strings containing multi-byte characters may lead to unexpected results. -:: +.. _REPLACE: + +.. code-block:: cmake string(REPLACE <match_string> - <replace_string> <output variable> + <replace_string> <output_variable> <input> [<input>...]) -Replace all occurrences of ``match_string`` in the input -with ``replace_string`` and store the result in the output. +Replace all occurrences of ``<match_string>`` in the ``<input>`` +with ``<replace_string>`` and store the result in the ``<output_variable>``. Regular Expressions ^^^^^^^^^^^^^^^^^^^ -REGEX MATCH -""""""""""" +.. _`REGEX MATCH`: -:: +.. code-block:: cmake string(REGEX MATCH <regular_expression> - <output variable> <input> [<input>...]) + <output_variable> <input> [<input>...]) -Match the regular expression once and store the match in the output variable. +Match the ``<regular_expression>`` once and store the match in the +``<output_variable>``. All ``<input>`` arguments are concatenated before matching. -REGEX MATCHALL -"""""""""""""" +.. _`REGEX MATCHALL`: -:: +.. code-block:: cmake string(REGEX MATCHALL <regular_expression> - <output variable> <input> [<input>...]) + <output_variable> <input> [<input>...]) -Match the regular expression as many times as possible and store the matches -in the output variable as a list. +Match the ``<regular_expression>`` as many times as possible and store the +matches in the ``<output_variable>`` as a list. All ``<input>`` arguments are concatenated before matching. -REGEX REPLACE -""""""""""""" +.. _`REGEX REPLACE`: -:: +.. code-block:: cmake string(REGEX REPLACE <regular_expression> - <replace_expression> <output variable> + <replacement_expression> <output_variable> <input> [<input>...]) -Match the regular expression as many times as possible and substitute the -replacement expression for the match in the output. +Match the ``<regular_expression>`` as many times as possible and substitute +the ``<replacement_expression>`` for the match in the output. All ``<input>`` arguments are concatenated before matching. -The replace expression may refer to paren-delimited subexpressions of the -match using ``\1``, ``\2``, ..., ``\9``. Note that two backslashes (``\\1``) -are required in CMake code to get a backslash through argument parsing. +The ``<replacement_expression>`` may refer to parenthesis-delimited +subexpressions of the match using ``\1``, ``\2``, ..., ``\9``. Note that +two backslashes (``\\1``) are required in CMake code to get a backslash +through argument parsing. .. _`Regex Specification`: @@ -90,6 +129,11 @@ The following characters have special meaning in regular expressions: Matches at end of input ``.`` Matches any single character +``\<char>`` + Matches the single character specified by ``<char>``. Use this to + match special regex characters, e.g. ``\.`` for a literal ``.`` + or ``\\`` for a literal backslash ``\``. Escaping a non-special + character is unnecessary but allowed, e.g. ``\a`` matches ``a``. ``[ ]`` Matches any character(s) inside the brackets ``[^ ]`` @@ -120,114 +164,161 @@ has lower precedence than concatenation. This means that the regular expression ``^ab+d$`` matches ``abbd`` but not ``ababd``, and the regular expression ``^(ab|cd)$`` matches ``ab`` but not ``abd``. +CMake language :ref:`Escape Sequences` such as ``\t``, ``\r``, ``\n``, +and ``\\`` may be used to construct literal tabs, carriage returns, +newlines, and backslashes (respectively) to pass in a regex. For example: + +* The quoted argument ``"[ \t\r\n]"`` specifies a regex that matches + any single whitespace character. +* The quoted argument ``"[/\\]"`` specifies a regex that matches + a single forward slash ``/`` or backslash ``\``. +* The quoted argument ``"[A-Za-z0-9_]"`` specifies a regex that matches + any single "word" character in the C locale. +* The quoted argument ``"\\(\\a\\+b\\)"`` specifies a regex that matches + the exact string ``(a+b)``. Each ``\\`` is parsed in a quoted argument + as just ``\``, so the regex itself is actually ``\(\a\+\b\)``. This + can alternatively be specified in a :ref:`bracket argument` without + having to escape the backslashes, e.g. ``[[\(\a\+\b\)]]``. + Manipulation ^^^^^^^^^^^^ -APPEND -"""""" +.. _APPEND: -:: +.. code-block:: cmake - string(APPEND <string variable> [<input>...]) + string(APPEND <string_variable> [<input>...]) -Append all the input arguments to the string. +Append all the ``<input>`` arguments to the string. -CONCAT -"""""" +.. _PREPEND: -:: +.. code-block:: cmake - string(CONCAT <output variable> [<input>...]) + string(PREPEND <string_variable> [<input>...]) -Concatenate all the input arguments together and store -the result in the named output variable. +Prepend all the ``<input>`` arguments to the string. -TOLOWER -""""""" +.. _CONCAT: -:: +.. code-block:: cmake - string(TOLOWER <string1> <output variable>) + string(CONCAT <output_variable> [<input>...]) -Convert string to lower characters. +Concatenate all the ``<input>`` arguments together and store +the result in the named ``<output_variable>``. -TOUPPER -""""""" +.. _JOIN: -:: +.. code-block:: cmake - string(TOUPPER <string1> <output variable>) + string(JOIN <glue> <output_variable> [<input>...]) -Convert string to upper characters. +Join all the ``<input>`` arguments together using the ``<glue>`` +string and store the result in the named ``<output_variable>``. -LENGTH -"""""" +To join a list's elements, prefer to use the ``JOIN`` operator +from the :command:`list` command. This allows for the elements to have +special characters like ``;`` in them. -:: +.. _TOLOWER: - string(LENGTH <string> <output variable>) +.. code-block:: cmake -Store in an output variable a given string's length. + string(TOLOWER <string> <output_variable>) -SUBSTRING -""""""""" +Convert ``<string>`` to lower characters. -:: +.. _TOUPPER: + +.. code-block:: cmake + + string(TOUPPER <string> <output_variable>) + +Convert ``<string>`` to upper characters. + +.. _LENGTH: + +.. code-block:: cmake + + string(LENGTH <string> <output_variable>) + +Store in an ``<output_variable>`` a given string's length in bytes. +Note that this means if ``<string>`` contains multi-byte characters, the +result stored in ``<output_variable>`` will *not* be the number of characters. + +.. _SUBSTRING: + +.. code-block:: cmake - string(SUBSTRING <string> <begin> <length> <output variable>) + string(SUBSTRING <string> <begin> <length> <output_variable>) -Store in an output variable a substring of a given string. If length is -``-1`` the remainder of the string starting at begin will be returned. -If string is shorter than length then end of string is used instead. +Store in an ``<output_variable>`` a substring of a given ``<string>``. If +``<length>`` is ``-1`` the remainder of the string starting at ``<begin>`` +will be returned. If ``<string>`` is shorter than ``<length>`` then the +end of the string is used instead. + +Both ``<begin>`` and ``<length>`` are counted in bytes, so care must +be exercised if ``<string>`` could contain multi-byte characters. .. note:: - CMake 3.1 and below reported an error if length pointed past - the end of string. + CMake 3.1 and below reported an error if ``<length>`` pointed past + the end of ``<string>``. -STRIP -""""" +.. _STRIP: -:: +.. code-block:: cmake - string(STRIP <string> <output variable>) + string(STRIP <string> <output_variable>) -Store in an output variable a substring of a given string with leading and -trailing spaces removed. +Store in an ``<output_variable>`` a substring of a given ``<string>`` with +leading and trailing spaces removed. -GENEX_STRIP -""""""""""" +.. _GENEX_STRIP: -:: +.. code-block:: cmake - string(GENEX_STRIP <input string> <output variable>) + string(GENEX_STRIP <string> <output_variable>) Strip any :manual:`generator expressions <cmake-generator-expressions(7)>` -from the ``input string`` and store the result in the ``output variable``. +from the input ``<string>`` and store the result in the ``<output_variable>``. + +.. _REPEAT: + +.. code-block:: cmake + + string(REPEAT <string> <count> <output_variable>) + +Produce the output string as the input ``<string>`` repeated ``<count>`` times. Comparison ^^^^^^^^^^ -:: +.. _COMPARE: + +.. code-block:: cmake - string(COMPARE LESS <string1> <string2> <output variable>) - string(COMPARE GREATER <string1> <string2> <output variable>) - string(COMPARE EQUAL <string1> <string2> <output variable>) - string(COMPARE NOTEQUAL <string1> <string2> <output variable>) - string(COMPARE LESS_EQUAL <string1> <string2> <output variable>) - string(COMPARE GREATER_EQUAL <string1> <string2> <output variable>) + string(COMPARE LESS <string1> <string2> <output_variable>) + string(COMPARE GREATER <string1> <string2> <output_variable>) + string(COMPARE EQUAL <string1> <string2> <output_variable>) + string(COMPARE NOTEQUAL <string1> <string2> <output_variable>) + string(COMPARE LESS_EQUAL <string1> <string2> <output_variable>) + string(COMPARE GREATER_EQUAL <string1> <string2> <output_variable>) -Compare the strings and store true or false in the output variable. +Compare the strings and store true or false in the ``<output_variable>``. .. _`Supported Hash Algorithms`: Hashing ^^^^^^^ -:: +.. _`HASH`: - string(<HASH> <output variable> <input>) +.. code-block:: cmake -Compute a cryptographic hash of the input string. + string(<HASH> <output_variable> <input>) + +Compute a cryptographic hash of the ``<input>`` string. The supported ``<HASH>`` algorithm names are: ``MD5`` @@ -254,56 +345,63 @@ The supported ``<HASH>`` algorithm names are: Generation ^^^^^^^^^^ -ASCII -""""" +.. _ASCII: -:: +.. code-block:: cmake - string(ASCII <number> [<number> ...] <output variable>) + string(ASCII <number> [<number> ...] <output_variable>) Convert all numbers into corresponding ASCII characters. -CONFIGURE -""""""""" +.. _CONFIGURE: -:: +.. code-block:: cmake - string(CONFIGURE <string1> <output variable> + string(CONFIGURE <string> <output_variable> [@ONLY] [ESCAPE_QUOTES]) -Transform a string like :command:`configure_file` transforms a file. +Transform a ``<string>`` like :command:`configure_file` transforms a file. -RANDOM -"""""" +.. _MAKE_C_IDENTIFIER: -:: +.. code-block:: cmake + + string(MAKE_C_IDENTIFIER <string> <output_variable>) + +Convert each non-alphanumeric character in the input ``<string>`` to an +underscore and store the result in the ``<output_variable>``. If the first +character of the ``<string>`` is a digit, an underscore will also be prepended +to the result. + +.. _RANDOM: + +.. code-block:: cmake string(RANDOM [LENGTH <length>] [ALPHABET <alphabet>] - [RANDOM_SEED <seed>] <output variable>) + [RANDOM_SEED <seed>] <output_variable>) -Return a random string of given length consisting of -characters from the given alphabet. Default length is 5 characters +Return a random string of given ``<length>`` consisting of +characters from the given ``<alphabet>``. Default length is 5 characters and default alphabet is all numbers and upper and lower case letters. If an integer ``RANDOM_SEED`` is given, its value will be used to seed the random number generator. -TIMESTAMP -""""""""" +.. _TIMESTAMP: -:: +.. code-block:: cmake - string(TIMESTAMP <output variable> [<format string>] [UTC]) + string(TIMESTAMP <output_variable> [<format_string>] [UTC]) Write a string representation of the current date -and/or time to the output variable. +and/or time to the ``<output_variable>``. -Should the command be unable to obtain a timestamp the output variable -will be set to the empty string "". +If the command is unable to obtain a timestamp, the ``<output_variable>`` +will be set to the empty string ``""``. The optional ``UTC`` flag requests the current date/time representation to be in Coordinated Universal Time (UTC) rather than local time. -The optional ``<format string>`` may contain the following format +The optional ``<format_string>`` may contain the following format specifiers: :: @@ -315,6 +413,7 @@ specifiers: %j The day of the current year (001-366). %m The month of the current year (01-12). %b Abbreviated month name (e.g. Oct). + %B Full month name (e.g. October). %M The minute of the current hour (00-59). %s Seconds since midnight (UTC) 1-Jan-1970 (UNIX time). %S The second of the current minute. @@ -322,46 +421,39 @@ specifiers: %U The week number of the current year (00-53). %w The day of the current week. 0 is Sunday. (0-6) %a Abbreviated weekday name (e.g. Fri). + %A Full weekday name (e.g. Friday). %y The last two digits of the current year (00-99) %Y The current year. Unknown format specifiers will be ignored and copied to the output as-is. -If no explicit ``<format string>`` is given it will default to: +If no explicit ``<format_string>`` is given, it will default to: :: %Y-%m-%dT%H:%M:%S for local time. %Y-%m-%dT%H:%M:%SZ for UTC. - -:: - - string(MAKE_C_IDENTIFIER <input string> <output variable>) - -Write a string which can be used as an identifier in C. - .. note:: If the ``SOURCE_DATE_EPOCH`` environment variable is set, its value will be used instead of the current time. See https://reproducible-builds.org/specs/source-date-epoch/ for details. -UUID -"""" +.. _UUID: -:: +.. code-block:: cmake - string(UUID <output variable> NAMESPACE <namespace> NAME <name> + string(UUID <output_variable> NAMESPACE <namespace> NAME <name> TYPE <MD5|SHA1> [UPPER]) -Create a univerally unique identifier (aka GUID) as per RFC4122 +Create a universally unique identifier (aka GUID) as per RFC4122 based on the hash of the combined values of ``<namespace>`` (which itself has to be a valid UUID) and ``<name>``. The hash algorithm can be either ``MD5`` (Version 3 UUID) or ``SHA1`` (Version 5 UUID). A UUID has the format ``xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx`` -where each `x` represents a lower case hexadecimal character. -Where required an uppercase representation can be requested +where each ``x`` represents a lower case hexadecimal character. +Where required, an uppercase representation can be requested with the optional ``UPPER`` flag. |