file ---- File manipulation command. ------------------------------------------------------------------------------ :: file(WRITE <filename> <content>...) file(APPEND <filename> <content>...) Write ``<content>`` into a file called ``<filename>``. If the file does not exist, it will be created. If the file already exists, ``WRITE`` mode will overwrite it and ``APPEND`` mode will append to the end. (If the file is a build input, use the :command:`configure_file` command to update the file only when its content changes.) ------------------------------------------------------------------------------ :: file(READ <filename> <variable> [OFFSET <offset>] [LIMIT <max-in>] [HEX]) Read content from a file called ``<filename>`` and store it in a ``<variable>``. Optionally start from the given ``<offset>`` and read at most ``<max-in>`` bytes. The ``HEX`` option causes data to be converted to a hexadecimal representation (useful for binary data). ------------------------------------------------------------------------------ :: file(STRINGS <filename> <variable> [<options>...]) Parse a list of ASCII strings from ``<filename>`` and store it in ``<variable>``. Binary data in the file are ignored. Carriage return (``\r``, CR) characters are ignored. The options are: ``LENGTH_MAXIMUM <max-len>`` Consider only strings of at most a given length. ``LENGTH_MINIMUM <min-len>`` Consider only strings of at least a given length. ``LIMIT_COUNT <max-num>`` Limit the number of distinct strings to be extracted. ``LIMIT_INPUT <max-in>`` Limit the number of input bytes to read from the file. ``LIMIT_OUTPUT <max-out>`` Limit the number of total bytes to store in the ``<variable>``. ``NEWLINE_CONSUME`` Treat newline characters (``\n``, LF) as part of string content instead of terminating at them. ``NO_HEX_CONVERSION`` Intel Hex and Motorola S-record files are automatically converted to binary while reading unless this option is given. ``REGEX <regex>`` Consider only strings that match the given regular expression. ``ENCODING <encoding-type>`` Consider strings of a given encoding. Currently supported encodings are: UTF-8, UTF-16LE, UTF-16BE, UTF-32LE, UTF-32BE. If the ENCODING option is not provided and the file has a Byte Order Mark, the ENCODING option will be defaulted to respect the Byte Order Mark. For example, the code .. code-block:: cmake file(STRINGS myfile.txt myfile) stores a list in the variable ``myfile`` in which each item is a line from the input file. ------------------------------------------------------------------------------ :: file(<MD5|SHA1|SHA224|SHA256|SHA384|SHA512> <filename> <variable>) Compute a cryptographic hash of the content of ``<filename>`` and store it in a ``<variable>``. ------------------------------------------------------------------------------ :: file(GLOB <variable> [LIST_DIRECTORIES true|false] [RELATIVE <path>] [<globbing-expressions>...]) file(GLOB_RECURSE <variable> [FOLLOW_SYMLINKS] [LIST_DIRECTORIES true|false] [RELATIVE <path>] [<globbing-expressions>...]) Generate a list of files that match the ``<globbing-expressions>`` and store it into the ``<variable>``. Globbing expressions are similar to regular expressions, but much simpler. If ``RELATIVE`` flag is specified, the results will be returned as relative paths to the given path. By default ``GLOB`` lists directories - directories are omited in result if ``LIST_DIRECTORIES`` is set to false. .. note:: We do not recommend using GLOB to collect a list of source files from your source tree. If no CMakeLists.txt file changes when a source is added or removed then the generated build system cannot know when to ask CMake to regenerate. Examples of globbing expressions include:: *.cxx - match all files with extension cxx *.vt? - match all files with extension vta,...,vtz f[3-5].txt - match files f3.txt, f4.txt, f5.txt The ``GLOB_RECURSE`` mode will traverse all the subdirectories of the matched directory and match the files. Subdirectories that are symlinks are only traversed if ``FOLLOW_SYMLINKS`` is given or policy :policy:`CMP0009` is not set to ``NEW``. By default ``GLOB_RECURSE`` omits directories from result list - setting ``LIST_DIRECTORIES`` to true adds directories to result list. If ``FOLLOW_SYMLINKS`` is given or policy :policy:`CMP0009` is not set to ``OLD`` then ``LIST_DIRECTORIES`` treats symlinks as directories. Examples of recursive globbing include:: /dir/*.py - match all python files in /dir and subdirectories ------------------------------------------------------------------------------ :: file(RENAME <oldname> <newname>) Move a file or directory within a filesystem from ``<oldname>`` to ``<newname>``, replacing the destination atomically. ------------------------------------------------------------------------------ :: file(REMOVE [<files>...]) file(REMOVE_RECURSE [<files>...]) Remove the given files. The ``REMOVE_RECURSE`` mode will remove the given files and directories, also non-empty directories ------------------------------------------------------------------------------ :: file(MAKE_DIRECTORY [<directories>...]) Create the given directories and their parents as needed. ------------------------------------------------------------------------------ :: file(RELATIVE_PATH <variable> <directory> <file>) Compute the relative path from a ``<directory>`` to a ``<file>`` and store it in the ``<variable>``. ------------------------------------------------------------------------------ :: file(TO_CMAKE_PATH "<path>" <variable>) file(TO_NATIVE_PATH "<path>" <variable>) The ``TO_CMAKE_PATH`` mode converts a native ``<path>`` into a cmake-style path with forward-slashes (``/``). The input can be a single path or a system search path like ``$ENV{PATH}``. A search path will be converted to a cmake-style list separated by ``;`` characters. The ``TO_NATIVE_PATH`` mode converts a cmake-style ``<path>`` into a native path with platform-specific slashes (``\`` on Windows and ``/`` elsewhere). Always use double quotes around the ``<path>`` to be sure it is treated as a single argument to this command. ------------------------------------------------------------------------------ :: file(DOWNLOAD <url> <file> [<options>...]) file(UPLOAD <file> <url> [<options>...]) The ``DOWNLOAD`` mode downloads the given ``<url>`` to a local ``<file>``. The ``UPLOAD`` mode uploads a local ``<file>`` to a given ``<url>``. Options to both ``DOWNLOAD`` and ``UPLOAD`` are: ``INACTIVITY_TIMEOUT <seconds>`` Terminate the operation after a period of inactivity. ``LOG <variable>`` Store a human-readable log of the operation in a variable. ``SHOW_PROGRESS`` Print progress information as status messages until the operation is complete. ``STATUS <variable>`` Store the resulting status of the operation in a variable. The status is a ``;`` separated list of length 2. The first element is the numeric return value for the operation, and the second element is a string value for the error. A ``0`` numeric error means no error in the operation. ``TIMEOUT <seconds>`` Terminate the operation after a given total time has elapsed. Additional options to ``DOWNLOAD`` are: ``EXPECTED_HASH ALGO=<value>`` Verify that the downloaded content hash matches the expected value, where ``ALGO`` is one of ``MD5``, ``SHA1``, ``SHA224``, ``SHA256``, ``SHA384``, or ``SHA512``. If it does not match, the operation fails with an error. ``EXPECTED_MD5 <value>`` Historical short-hand for ``EXPECTED_HASH MD5=<value>``. ``TLS_VERIFY <ON|OFF>`` Specify whether to verify the server certificate for ``https://`` URLs. The default is to *not* verify. ``TLS_CAINFO <file>`` Specify a custom Certificate Authority file for ``https://`` URLs. For ``https://`` URLs CMake must be built with OpenSSL support. ``TLS/SSL`` certificates are not checked by default. Set ``TLS_VERIFY`` to ``ON`` to check certificates and/or use ``EXPECTED_HASH`` to verify downloaded content. If neither ``TLS`` option is given CMake will check variables ``CMAKE_TLS_VERIFY`` and ``CMAKE_TLS_CAINFO``, respectively. ------------------------------------------------------------------------------ :: file(TIMESTAMP <filename> <variable> [<format>] [UTC]) Compute a string representation of the modification time of ``<filename>`` and store it in ``<variable>``. Should the command be unable to obtain a timestamp variable will be set to the empty string (""). See the :command:`string(TIMESTAMP)` command for documentation of the ``<format>`` and ``UTC`` options. ------------------------------------------------------------------------------ :: file(GENERATE OUTPUT output-file <INPUT input-file|CONTENT content> [CONDITION expression]) Generate an output file for each build configuration supported by the current :manual:`CMake Generator <cmake-generators(7)>`. Evaluate :manual:`generator expressions <cmake-generator-expressions(7)>` from the input content to produce the output content. The options are: ``CONDITION <condition>`` Generate the output file for a particular configuration only if the condition is true. The condition must be either ``0`` or ``1`` after evaluating generator expressions. ``CONTENT <content>`` Use the content given explicitly as input. ``INPUT <input-file>`` Use the content from a given file as input. ``OUTPUT <output-file>`` Specify the output file name to generate. Use generator expressions such as ``$<CONFIG>`` to specify a configuration-specific output file name. Multiple configurations may generate the same output file only if the generated content is identical. Otherwise, the ``<output-file>`` must evaluate to an unique name for each configuration. Exactly one ``CONTENT`` or ``INPUT`` option must be given. A specific ``OUTPUT`` file may be named by at most one invocation of ``file(GENERATE)``. Generated files are modified on subsequent cmake runs only if their content is changed. ------------------------------------------------------------------------------ :: file(<COPY|INSTALL> <files>... DESTINATION <dir> [FILE_PERMISSIONS <permissions>...] [DIRECTORY_PERMISSIONS <permissions>...] [NO_SOURCE_PERMISSIONS] [USE_SOURCE_PERMISSIONS] [FILES_MATCHING] [[PATTERN <pattern> | REGEX <regex>] [EXCLUDE] [PERMISSIONS <permissions>...]] [...]) The ``COPY`` signature copies files, directories, and symlinks to a destination folder. Relative input paths are evaluated with respect to the current source directory, and a relative destination is evaluated with respect to the current build directory. Copying preserves input file timestamps, and optimizes out a file if it exists at the destination with the same timestamp. Copying preserves input permissions unless explicit permissions or ``NO_SOURCE_PERMISSIONS`` are given (default is ``USE_SOURCE_PERMISSIONS``). See the :command:`install(DIRECTORY)` command for documentation of permissions, ``FILES_MATCHING``, ``PATTERN``, ``REGEX``, and ``EXCLUDE`` options. Copying directories preserves the structure of their content even if options are used to select a subset of files. The ``INSTALL`` signature differs slightly from ``COPY``: it prints status messages (subject to the :variable:`CMAKE_INSTALL_MESSAGE` variable), and ``NO_SOURCE_PERMISSIONS`` is default. Installation scripts generated by the :command:`install` command use this signature (with some undocumented options for internal use). ------------------------------------------------------------------------------ :: file(LOCK <path> [DIRECTORY] [RELEASE] [GUARD <FUNCTION|FILE|PROCESS>] [RESULT_VARIABLE <variable>] [TIMEOUT <seconds>]) Lock a file specified by ``<path>`` if no ``DIRECTORY`` option present and file ``<path>/cmake.lock`` otherwise. File will be locked for scope defined by ``GUARD`` option (default value is ``PROCESS``). ``RELEASE`` option can be used to unlock file explicitly. If option ``TIMEOUT`` is not specified CMake will wait until lock succeed or until fatal error occurs. If ``TIMEOUT`` is set to ``0`` lock will be tried once and result will be reported immediately. If ``TIMEOUT`` is not ``0`` CMake will try to lock file for the period specified by ``<seconds>`` value. Any errors will be interpreted as fatal if there is no ``RESULT_VARIABLE`` option. Otherwise result will be stored in ``<variable>`` and will be ``0`` on success or error message on failure. Note that lock is advisory - there is no guarantee that other processes will respect this lock, i.e. lock synchronize two or more CMake instances sharing some modifiable resources. Similar logic applied to ``DIRECTORY`` option - locking parent directory doesn't prevent other ``LOCK`` commands to lock any child directory or file. Trying to lock file twice is not allowed. Any intermediate directories and file itself will be created if they not exist. ``GUARD`` and ``TIMEOUT`` options ignored on ``RELEASE`` operation.