Help: Format and revise file() command documentation

Organize the documentation by sub-command to keep the signatures and
their descriptions nearby.  Use inline and explicit reST markup.  Revise
wording as necessary for the updated layout.  Clarify behavior of the
file(GENERATE) command w.r.t. conflicting file names.
This commit is contained in:
Brad King 2014-05-23 16:16:47 -04:00
parent 8ae05b420e
commit d74ed5431a
1 changed files with 260 additions and 172 deletions

View File

@ -3,211 +3,299 @@ file
File manipulation command.
::
file(WRITE filename "message to write"... )
file(APPEND filename "message to write"... )
file(READ filename variable [LIMIT numBytes] [OFFSET offset] [HEX])
file(<MD5|SHA1|SHA224|SHA256|SHA384|SHA512> filename variable)
file(STRINGS filename variable [LIMIT_COUNT num]
[LIMIT_INPUT numBytes] [LIMIT_OUTPUT numBytes]
[LENGTH_MINIMUM numBytes] [LENGTH_MAXIMUM numBytes]
[NEWLINE_CONSUME] [REGEX regex]
[NO_HEX_CONVERSION])
file(GLOB variable [RELATIVE path] [globbing expressions]...)
file(GLOB_RECURSE variable [RELATIVE path]
[FOLLOW_SYMLINKS] [globbing expressions]...)
file(RENAME <oldname> <newname>)
file(REMOVE [file1 ...])
file(REMOVE_RECURSE [file1 ...])
file(MAKE_DIRECTORY [directory1 directory2 ...])
file(RELATIVE_PATH variable directory file)
file(TO_CMAKE_PATH path result)
file(TO_NATIVE_PATH path result)
file(DOWNLOAD url file [INACTIVITY_TIMEOUT timeout]
[TIMEOUT timeout] [STATUS status] [LOG log] [SHOW_PROGRESS]
[EXPECTED_HASH ALGO=value] [EXPECTED_MD5 sum]
[TLS_VERIFY on|off] [TLS_CAINFO file])
file(UPLOAD filename url [INACTIVITY_TIMEOUT timeout]
[TIMEOUT timeout] [STATUS status] [LOG log] [SHOW_PROGRESS])
file(TIMESTAMP filename variable [<format string>] [UTC])
file(GENERATE OUTPUT output_file
<INPUT input_file|CONTENT input_content>
[CONDITION expression])
WRITE will write a message into a file called 'filename'. It
overwrites the file if it already exists, and creates the file if it
does not exist. (If the file is a build input, use configure_file to
update the file only when its content changes.)
APPEND will write a message into a file same as WRITE, except it will
append it to the end of the file
READ will read the content of a file and store it into the variable.
It will start at the given offset and read up to numBytes. If the
argument HEX is given, the binary data will be converted to
hexadecimal representation and this will be stored in the variable.
MD5, SHA1, SHA224, SHA256, SHA384, and SHA512 will compute a
cryptographic hash of the content of a file.
STRINGS will parse a list of ASCII strings from a file and store it in
a variable. Binary data in the file are ignored. Carriage return
(CR) characters are ignored. It works also for Intel Hex and Motorola
S-record files, which are automatically converted to binary format
when reading them. Disable this using NO_HEX_CONVERSION.
LIMIT_COUNT sets the maximum number of strings to return. LIMIT_INPUT
sets the maximum number of bytes to read from the input file.
LIMIT_OUTPUT sets the maximum number of bytes to store in the output
variable. LENGTH_MINIMUM sets the minimum length of a string to
return. Shorter strings are ignored. LENGTH_MAXIMUM sets the maximum
length of a string to return. Longer strings are split into strings
no longer than the maximum length. NEWLINE_CONSUME allows newlines to
be included in strings instead of terminating them.
REGEX specifies a regular expression that a string must match to be
returned. Typical usage
------------------------------------------------------------------------------
::
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.
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
stores a list in the variable ``myfile`` in which each item is a line
from the input file.
GLOB will generate a list of all 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 for an expression, the results will be returned as a
relative path to the given path. (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
file(<MD5|SHA1|SHA224|SHA256|SHA384|SHA512> <filename> <variable>)
GLOB_RECURSE will generate a list similar to the regular GLOB, except
it 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 cmake policy CMP0009 is not set to NEW.
See cmake --help-policy CMP0009 for more information.
Compute a cryptographic hash of the content of ``<filename>`` and
store it in a ``<variable>``.
Examples of recursive globbing include:
------------------------------------------------------------------------------
::
/dir/*.py - match all python files in /dir and subdirectories
file(GLOB <variable> [RELATIVE <path>] [<globbing-expressions>...])
file(GLOB_RECURSE <variable> [RELATIVE <path>]
[FOLLOW_SYMLINKS] [<globbing-expressions>...])
MAKE_DIRECTORY will create the given directories, also if their parent
directories don't exist yet
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.
RENAME moves a file or directory within a filesystem, replacing the
destination atomically.
.. 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.
REMOVE will remove the given files, also in subdirectories
Examples of globbing expressions include::
REMOVE_RECURSE will remove the given files and directories, also
non-empty directories
*.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
RELATIVE_PATH will determine relative path from directory to the given
file.
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``.
TO_CMAKE_PATH will convert path into a cmake style path with unix /.
The input can be a single path or a system path like "$ENV{PATH}".
Note the double quotes around the ENV call TO_CMAKE_PATH only takes
one argument. This command will also convert the native list
delimiters for a list of paths like the PATH environment variable.
Examples of recursive globbing include::
TO_NATIVE_PATH works just like TO_CMAKE_PATH, but will convert from a
cmake style path into the native path style \ for windows and / for
UNIX.
/dir/*.py - match all python files in /dir and subdirectories
DOWNLOAD will download the given URL to the given file. If LOG var is
specified a log of the download will be put in var. If STATUS var is
specified the status of the operation will be put in var. The status
is returned in a 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. If TIMEOUT time is specified, the operation will timeout
after time seconds, time should be specified as an integer. The
INACTIVITY_TIMEOUT specifies an integer number of seconds of
inactivity after which the operation should terminate. If
EXPECTED_HASH ALGO=value is specified, the operation will verify that
the downloaded file's actual 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
sum" is short-hand for "EXPECTED_HASH MD5=sum".) If SHOW_PROGRESS is
specified, progress information will be printed as status messages
until the operation is complete. For https URLs CMake must be built
with OpenSSL. 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. Set TLS_CAINFO to specify a custom
Certificate Authority file. If either TLS option is not given CMake
will check variables CMAKE_TLS_VERIFY and CMAKE_TLS_CAINFO,
respectively.
UPLOAD will upload the given file to the given URL. If LOG var is
specified a log of the upload will be put in var. If STATUS var is
specified the status of the operation will be put in var. The status
is returned in a 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. If TIMEOUT time is specified, the operation will timeout
after time seconds, time should be specified as an integer. The
INACTIVITY_TIMEOUT specifies an integer number of seconds of
inactivity after which the operation should terminate. If
SHOW_PROGRESS is specified, progress information will be printed as
status messages until the operation is complete.
TIMESTAMP will write a string representation of the modification time
of filename to variable.
Should the command be unable to obtain a timestamp variable will be
set to the empty string "".
See documentation of the string TIMESTAMP sub-command for more
details.
The file() command also provides COPY and INSTALL signatures:
------------------------------------------------------------------------------
::
file(<COPY|INSTALL> files... DESTINATION <dir>
[FILE_PERMISSIONS permissions...]
[DIRECTORY_PERMISSIONS permissions...]
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 <options>...)
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)``.
------------------------------------------------------------------------------
::
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...]] [...])
[EXCLUDE] [PERMISSIONS <permissions>...]] [...])
The COPY signature copies files, directories, and symlinks to a
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 install(DIRECTORY)
command for documentation of permissions, PATTERN, REGEX, and EXCLUDE
options.
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, ``PATTERN``, ``REGEX``, and ``EXCLUDE`` options.
The INSTALL signature differs slightly from COPY: it prints status
messages, and NO_SOURCE_PERMISSIONS is default. Installation scripts
generated by the install() command use this signature (with some
undocumented options for internal use).
GENERATE will write an <output_file> with content from an
<input_file>, or from <input_content>. The output is generated
conditionally based on the content of the <condition>. The file is
written at CMake generate-time and the input may contain generator
expressions. The <condition>, <output_file> and <input_file> may also
contain generator expressions. The <condition> must evaluate to
either '0' or '1'. The <output_file> must evaluate to a unique name
among all configurations and among all invocations of file(GENERATE).
The ``INSTALL`` signature differs slightly from ``COPY``: it prints
status messages, and ``NO_SOURCE_PERMISSIONS`` is default.
Installation scripts generated by the :command:`install` command
use this signature (with some undocumented options for internal use).