/usr/share/cmake-3.10/Help/command/string.rst is in cmake-data 3.10.2-1ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 | string
------
.. only:: html
.. contents::
String operations.
Search and Replace
^^^^^^^^^^^^^^^^^^
FIND
""""
::
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
search for the position of the last occurrence of the specified
substring. If the substring is not found, a position of -1 is returned.
REPLACE
"""""""
::
string(REPLACE <match_string>
<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.
Regular Expressions
^^^^^^^^^^^^^^^^^^^
REGEX MATCH
"""""""""""
::
string(REGEX MATCH <regular_expression>
<output variable> <input> [<input>...])
Match the regular expression once and store the match in the output variable.
All ``<input>`` arguments are concatenated before matching.
REGEX MATCHALL
""""""""""""""
::
string(REGEX MATCHALL <regular_expression>
<output variable> <input> [<input>...])
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
"""""""""""""
::
string(REGEX REPLACE <regular_expression>
<replace_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.
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.
.. _`Regex Specification`:
Regex Specification
"""""""""""""""""""
The following characters have special meaning in regular expressions:
``^``
Matches at beginning of input
``$``
Matches at end of input
``.``
Matches any single character
``[ ]``
Matches any character(s) inside the brackets
``[^ ]``
Matches any character(s) not inside the brackets
``-``
Inside brackets, specifies an inclusive range between
characters on either side e.g. ``[a-f]`` is ``[abcdef]``
To match a literal ``-`` using brackets, make it the first
or the last character e.g. ``[+*/-]`` matches basic
mathematical operators.
``*``
Matches preceding pattern zero or more times
``+``
Matches preceding pattern one or more times
``?``
Matches preceding pattern zero or once only
``|``
Matches a pattern on either side of the ``|``
``()``
Saves a matched subexpression, which can be referenced
in the ``REGEX REPLACE`` operation. Additionally it is saved
by all regular expression-related commands, including
e.g. :command:`if(MATCHES)`, in the variables
:variable:`CMAKE_MATCH_<n>` for ``<n>`` 0..9.
``*``, ``+`` and ``?`` have higher precedence than concatenation. ``|``
has lower precedence than concatenation. This means that the regular
expression ``^ab+d$`` matches ``abbd`` but not ``ababd``, and the regular
expression ``^(ab|cd)$`` matches ``ab`` but not ``abd``.
Manipulation
^^^^^^^^^^^^
APPEND
""""""
::
string(APPEND <string variable> [<input>...])
Append all the input arguments to the string.
PREPEND
"""""""
::
string(PREPEND <string variable> [<input>...])
Prepend all the input arguments to the string.
CONCAT
""""""
::
string(CONCAT <output variable> [<input>...])
Concatenate all the input arguments together and store
the result in the named output variable.
TOLOWER
"""""""
::
string(TOLOWER <string1> <output variable>)
Convert string to lower characters.
TOUPPER
"""""""
::
string(TOUPPER <string1> <output variable>)
Convert string to upper characters.
LENGTH
""""""
::
string(LENGTH <string> <output variable>)
Store in an output variable a given string's length.
SUBSTRING
"""""""""
::
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.
.. note::
CMake 3.1 and below reported an error if length pointed past
the end of string.
STRIP
"""""
::
string(STRIP <string> <output variable>)
Store in an output variable a substring of a given string with leading and
trailing spaces removed.
GENEX_STRIP
"""""""""""
::
string(GENEX_STRIP <input string> <output variable>)
Strip any :manual:`generator expressions <cmake-generator-expressions(7)>`
from the ``input string`` and store the result in the ``output variable``.
Comparison
^^^^^^^^^^
::
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.
.. _`Supported Hash Algorithms`:
Hashing
^^^^^^^
::
string(<HASH> <output variable> <input>)
Compute a cryptographic hash of the input string.
The supported ``<HASH>`` algorithm names are:
``MD5``
Message-Digest Algorithm 5, RFC 1321.
``SHA1``
US Secure Hash Algorithm 1, RFC 3174.
``SHA224``
US Secure Hash Algorithms, RFC 4634.
``SHA256``
US Secure Hash Algorithms, RFC 4634.
``SHA384``
US Secure Hash Algorithms, RFC 4634.
``SHA512``
US Secure Hash Algorithms, RFC 4634.
``SHA3_224``
Keccak SHA-3.
``SHA3_256``
Keccak SHA-3.
``SHA3_384``
Keccak SHA-3.
``SHA3_512``
Keccak SHA-3.
Generation
^^^^^^^^^^
ASCII
"""""
::
string(ASCII <number> [<number> ...] <output variable>)
Convert all numbers into corresponding ASCII characters.
CONFIGURE
"""""""""
::
string(CONFIGURE <string1> <output variable>
[@ONLY] [ESCAPE_QUOTES])
Transform a string like :command:`configure_file` transforms a file.
RANDOM
""""""
::
string(RANDOM [LENGTH <length>] [ALPHABET <alphabet>]
[RANDOM_SEED <seed>] <output variable>)
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
"""""""""
::
string(TIMESTAMP <output variable> [<format string>] [UTC])
Write a string representation of the current date
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 "".
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
specifiers:
::
%% A literal percent sign (%).
%d The day of the current month (01-31).
%H The hour on a 24-hour clock (00-23).
%I The hour on a 12-hour clock (01-12).
%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.
60 represents a leap second. (00-60)
%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:
::
%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
""""
::
string(UUID <output variable> NAMESPACE <namespace> NAME <name>
TYPE <MD5|SHA1> [UPPER])
Create a univerally 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
with the optional ``UPPER`` flag.
|