cmake(1)¶

Synopsis¶

Generate a Project Buildsystem
 cmake [<options>] -B <path-to-build> [-S <path-to-source>]
 cmake [<options>] <path-to-source | path-to-existing-build>

Build a Project
 cmake --build <dir> [<options>] [-- <build-tool-options>]

Install a Project
 cmake --install <dir> [<options>]

Open a Project
 cmake --open <dir>

Run a Script
 cmake [-D <var>=<value>]... -P <cmake-script-file>

Run a Command-Line Tool
 cmake -E <command> [<options>]

Run the Find-Package Tool
 cmake --find-package [<options>]

Run a Workflow Preset
 cmake --workflow [<options>]

View Help
 cmake --help[-<topic>]

Description¶

The cmake executable is the command-line interface of the cross-platform buildsystem generator CMake. The above Synopsis lists various actions the tool can perform as described in sections below.

To build a software project with CMake, Generate a Project Buildsystem. Optionally use cmake to Build a Project, Install a Project or just run the corresponding build tool (e.g. make) directly. cmake can also be used to View Help.

The other actions are meant for use by software developers writing scripts in the CMake language to support their builds.

For graphical user interfaces that may be used in place of cmake, see ccmake and cmake-gui. For command-line interfaces to the CMake testing and packaging facilities, see ctest and cpack.

For more information on CMake at large, see also the links at the end of this manual.

Introduction to CMake Buildsystems¶

A buildsystem describes how to build a project's executables and libraries from its source code using a build tool to automate the process. For example, a buildsystem may be a Makefile for use with a command-line make tool or a project file for an Integrated Development Environment (IDE). In order to avoid maintaining multiple such buildsystems, a project may specify its buildsystem abstractly using files written in the CMake language. From these files CMake generates a preferred buildsystem locally for each user through a backend called a generator.

To generate a buildsystem with CMake, the following must be selected:

Source Tree

The top-level directory containing source files provided by the project. The project specifies its buildsystem using files as described in the cmake-language(7) manual, starting with a top-level file named CMakeLists.txt. These files specify build targets and their dependencies as described in the cmake-buildsystem(7) manual.

Build Tree

The top-level directory in which buildsystem files and build output artifacts (e.g. executables and libraries) are to be stored. CMake will write a CMakeCache.txt file to identify the directory as a build tree and store persistent information such as buildsystem configuration options.

To maintain a pristine source tree, perform an out-of-source build by using a separate dedicated build tree. An in-source build in which the build tree is placed in the same directory as the source tree is also supported, but discouraged.

Generator

This chooses the kind of buildsystem to generate. See the cmake-generators(7) manual for documentation of all generators. Run cmake --help to see a list of generators available locally. Optionally use the -G option below to specify a generator, or simply accept the default CMake chooses for the current platform.

When using one of the Command-Line Build Tool Generators CMake expects that the environment needed by the compiler toolchain is already configured in the shell. When using one of the IDE Build Tool Generators, no particular environment is needed.

Generate a Project Buildsystem¶

Run CMake with one of the following command signatures to specify the source and build trees and generate a buildsystem:

cmake [<options>] -B <path-to-build> [-S <path-to-source>]

New in version 3.13.

Uses <path-to-build> as the build tree and <path-to-source> as the source tree. The specified paths may be absolute or relative to the current working directory. The source tree must contain a CMakeLists.txt file. The build tree will be created automatically if it does not already exist. For example:
$ cmake -S src -B build

cmake [<options>] <path-to-source>

Uses the current working directory as the build tree, and <path-to-source> as the source tree. The specified path may be absolute or relative to the current working directory. The source tree must contain a CMakeLists.txt file and must not contain a CMakeCache.txt file because the latter identifies an existing build tree. For example:

$ mkdir build ; cd build
$ cmake ../src

cmake [<options>] <path-to-existing-build>

Uses <path-to-existing-build> as the build tree, and loads the path to the source tree from its CMakeCache.txt file, which must have already been generated by a previous run of CMake. The specified path may be absolute or relative to the current working directory. For example:

$ cd build
$ cmake .

In all cases the <options> may be zero or more of the Options below.

The above styles for specifying the source and build trees may be mixed. Paths specified with -S or -B are always classified as source or build trees, respectively. Paths specified with plain arguments are classified based on their content and the types of paths given earlier. If only one type of path is given, the current working directory (cwd) is used for the other. For example:

Command Line	Source Dir	Build Dir
`cmake -B build`	cwd	`build`
`cmake -B build src`	`src`	`build`
`cmake -B build -S src`	`src`	`build`
`cmake src`	`src`	cwd
`cmake build` (existing)	loaded	`build`
`cmake -S src`	`src`	cwd
`cmake -S src build`	`src`	`build`
`cmake -S src -B build`	`src`	`build`

Changed in version 3.23: CMake warns when multiple source paths are specified. This has never been officially documented or supported, but older versions accidentally accepted multiple source paths and used the last path specified. Avoid passing multiple source path arguments.

After generating a buildsystem one may use the corresponding native build tool to build the project. For example, after using the Unix Makefiles generator one may run make directly:

$ make
$ make install

Alternatively, one may use cmake to Build a Project by automatically choosing and invoking the appropriate native build tool.

Options¶

-S <path-to-source>¶: Path to root directory of the CMake project to build.

-B <path-to-build>¶

Path to directory which CMake will use as the root of build directory.

If the directory doesn't already exist CMake will make it.

-C <initial-cache>¶

Pre-load a script to populate the cache.

When CMake is first run in an empty build tree, it creates a CMakeCache.txt file and populates it with customizable settings for the project. This option may be used to specify a file from which to load cache entries before the first pass through the project's CMake listfiles. The loaded entries take priority over the project's default values. The given file should be a CMake script containing set() commands that use the CACHE option, not a cache-format file.

References to CMAKE_SOURCE_DIR and CMAKE_BINARY_DIR within the script evaluate to the top-level source and build tree.

-D <var>:<type>=<value>, -D <var>=<value>¶

Create or update a CMake CACHE entry.

When CMake is first run in an empty build tree, it creates a CMakeCache.txt file and populates it with customizable settings for the project. This option may be used to specify a setting that takes priority over the project's default value. The option may be repeated for as many CACHE entries as desired.

If the :<type> portion is given it must be one of the types specified by the set() command documentation for its CACHE signature. If the :<type> portion is omitted the entry will be created with no type if it does not exist with a type already. If a command in the project sets the type to PATH or FILEPATH then the <value> will be converted to an absolute path.

This option may also be given as a single argument: -D<var>:<type>=<value> or -D<var>=<value>.

It's important to note that the order of -C and -D arguments is significant. They will be carried out in the order they are listed, with the last argument taking precedence over the previous ones. For example, if you specify -DCMAKE_BUILD_TYPE=Debug, followed by a -C argument with a file that calls:

set(CMAKE_BUILD_TYPE "Release" CACHE STRING "" FORCE)

then the -C argument will take precedence, and CMAKE_BUILD_TYPE will be set to Release. However, if the -D argument comes after the -C argument, it will be set to Debug.

If a set(... CACHE ...) call in the -C file does not use FORCE, and a -D argument sets the same variable, the -D argument will take precedence regardless of order because of the nature of non-FORCE set(... CACHE ...) calls.

-U <globbing_expr>¶

Remove matching entries from CMake CACHE.

This option may be used to remove one or more variables from the CMakeCache.txt file, globbing expressions using * and ? are supported. The option may be repeated for as many CACHE entries as desired.

Use with care, you can make your CMakeCache.txt non-working.

-G <generator-name>¶

Specify a build system generator.

CMake may support multiple native build systems on certain platforms. A generator is responsible for generating a particular build system. Possible generator names are specified in the cmake-generators(7) manual.

If not specified, CMake checks the CMAKE_GENERATOR environment variable and otherwise falls back to a builtin default selection.

-T <toolset-spec>¶

Toolset specification for the generator, if supported.

Some CMake generators support a toolset specification to tell the native build system how to choose a compiler. See the CMAKE_GENERATOR_TOOLSET variable for details.

-A <platform-name>¶

Specify platform name if supported by generator.

Some CMake generators support a platform name to be given to the native build system to choose a compiler or SDK. See the CMAKE_GENERATOR_PLATFORM variable for details.

--toolchain <path-to-file>¶: New in version 3.21.

Specify the cross compiling toolchain file, equivalent to setting CMAKE_TOOLCHAIN_FILE variable.

--install-prefix <directory>¶: New in version 3.21.

Specify the installation directory, used by the CMAKE_INSTALL_PREFIX variable. Must be an absolute path.

-Wno-dev¶

Suppress developer warnings.

Suppress warnings that are meant for the author of the CMakeLists.txt files. By default this will also turn off deprecation warnings.

-Wdev¶

Enable developer warnings.

Enable warnings that are meant for the author of the CMakeLists.txt files. By default this will also turn on deprecation warnings.

-Wdeprecated¶

Enable deprecated functionality warnings.

Enable warnings for usage of deprecated functionality, that are meant for the author of the CMakeLists.txt files.

-Wno-deprecated¶

Suppress deprecated functionality warnings.

Suppress warnings for usage of deprecated functionality, that are meant for the author of the CMakeLists.txt files.

-Werror=<what>¶

Treat CMake warnings as errors. <what> must be one of the following:

dev

Make developer warnings errors.

Make warnings that are meant for the author of the CMakeLists.txt files errors. By default this will also turn on deprecated warnings as errors.

deprecated

Make deprecated macro and function warnings errors.

Make warnings for usage of deprecated macros and functions, that are meant for the author of the CMakeLists.txt files, errors.

-Wno-error=<what>¶

Do not treat CMake warnings as errors. <what> must be one of the following:

dev: Make warnings that are meant for the author of the CMakeLists.txt files not errors. By default this will also turn off deprecated warnings as errors.
deprecated: Make warnings for usage of deprecated macros and functions, that are meant for the author of the CMakeLists.txt files, not errors.

--fresh¶: New in version 3.24.

Perform a fresh configuration of the build tree. This removes any existing CMakeCache.txt file and associated CMakeFiles/ directory, and recreates them from scratch.

-L[A][H]¶

List non-advanced cached variables.

List CACHE variables will run CMake and list all the variables from the CMake CACHE that are not marked as INTERNAL or ADVANCED. This will effectively display current CMake settings, which can then be changed with -D option. Changing some of the variables may result in more variables being created. If A is specified, then it will display also advanced variables. If H is specified, it will also display help for each variable.

-N¶

View mode only.

Only load the cache. Do not actually run configure and generate steps.

--graphviz=<file>¶

Generate graphviz of dependencies, see CMakeGraphVizOptions for more.

Generate a graphviz input file that will contain all the library and executable dependencies in the project. See the documentation for CMakeGraphVizOptions for more details.

--system-information [file]¶

Dump information about this system.

Dump a wide range of information about the current system. If run from the top of a binary tree for a CMake project it will dump additional information such as the cache, log files etc.

--log-level=<level>¶

Set the log <level>.

The message() command will only output messages of the specified log level or higher. The valid log levels are ERROR, WARNING, NOTICE, STATUS (default), VERBOSE, DEBUG, or TRACE.

To make a log level persist between CMake runs, set CMAKE_MESSAGE_LOG_LEVEL as a cache variable instead. If both the command line option and the variable are given, the command line option takes precedence.

For backward compatibility reasons, --loglevel is also accepted as a synonym for this option.

New in version 3.25: See the cmake_language() command for a way to query the current message logging level.

--log-context¶

Enable the message() command outputting context attached to each message.

This option turns on showing context for the current CMake run only. To make showing the context persistent for all subsequent CMake runs, set CMAKE_MESSAGE_CONTEXT_SHOW as a cache variable instead. When this command line option is given, CMAKE_MESSAGE_CONTEXT_SHOW is ignored.

--debug-trycompile¶

Do not delete the files and directories created for try_compile() / try_run() calls. This is useful in debugging failed checks.

Note that some uses of try_compile() may use the same build tree, which will limit the usefulness of this option if a project executes more than one try_compile(). For example, such uses may change results as artifacts from a previous try-compile may cause a different test to either pass or fail incorrectly. This option is best used only when debugging.

(With respect to the preceding, the try_run() command is effectively a try_compile(). Any combination of the two is subject to the potential issues described.)

New in version 3.25: When this option is enabled, every try-compile check prints a log message reporting the directory in which the check is performed.

--debug-output¶

Put cmake in a debug mode.

Print extra information during the cmake run like stack traces with message(SEND_ERROR) calls.

--debug-find¶

New in version 3.17.

Put cmake find commands in a debug mode.

Print extra find call information during the cmake run to standard error. Output is designed for human consumption and not for parsing. See also the CMAKE_FIND_DEBUG_MODE variable for debugging a more local part of the project.

--debug-find-pkg=<pkg>[,...]¶

New in version 3.23.

Put cmake find commands in a debug mode when running under calls to find_package(<pkg>), where <pkg> is an entry in the given comma-separated list of case-sensitive package names.

Like --debug-find, but limiting scope to the specified packages.

--debug-find-var=<var>[,...]¶

New in version 3.23.

Put cmake find commands in a debug mode when called with <var> as the result variable, where <var> is an entry in the given comma-separated list.

Like --debug-find, but limiting scope to the specified variable names.

--trace¶

Put cmake in trace mode.

Print a trace of all calls made and from where.

--trace-expand¶

Put cmake in trace mode.

Like --trace, but with variables expanded.

--trace-format=<format>¶

New in version 3.17.

Put cmake in trace mode and sets the trace output format.

<format> can be one of the following values.

human
Prints each trace line in a human-readable format. This is the default format.

json-v1
Prints each line as a separate JSON document. Each document is separated by a newline ( \n ). It is guaranteed that no newline characters will be present inside a JSON document.
JSON trace format¶
{
  "file": "/full/path/to/the/CMake/file.txt",
  "line": 0,
  "cmd": "add_executable",
  "args": ["foo", "bar"],
  "time": 1579512535.9687231,
  "frame": 2,
  "global_frame": 4
}
The members are:

file
The full path to the CMake source file where the function was called.

line
The line in file where the function call begins.

line_end
If the function call spans multiple lines, this field will be set to the line where the function call ends. If the function calls spans a single line, this field will be unset. This field was added in minor version 2 of the json-v1 format.

defer
Optional member that is present when the function call was deferred by cmake_language(DEFER). If present, its value is a string containing the deferred call <id>.

cmd
The name of the function that was called.

args
A string list of all function parameters.

time
Timestamp (seconds since epoch) of the function call.

frame
Stack frame depth of the function that was called, within the context of the CMakeLists.txt being processed currently.

global_frame
Stack frame depth of the function that was called, tracked globally across all CMakeLists.txt files involved in the trace. This field was added in minor version 2 of the json-v1 format.

Additionally, the first JSON document outputted contains the version key for the current major and minor version of the
JSON version format¶
{
  "version": {
    "major": 1,
    "minor": 2
  }
}
The members are:

version
Indicates the version of the JSON format. The version has a major and minor components following semantic version conventions.

--trace-source=<file>¶

Put cmake in trace mode, but output only lines of a specified file.

Multiple options are allowed.

--trace-redirect=<file>¶: Put cmake in trace mode and redirect trace output to a file instead of stderr.

--warn-uninitialized¶

Warn about uninitialized values.

Print a warning when an uninitialized variable is used.

--warn-unused-vars¶: Does nothing. In CMake versions 3.2 and below this enabled warnings about unused variables. In CMake versions 3.3 through 3.18 the option was broken. In CMake 3.19 and above the option has been removed.

--no-warn-unused-cli¶

Don't warn about command line options.

Don't find variables that are declared on the command line, but not used.

--check-system-vars¶

Find problems with variable usage in system files.

Normally, unused and uninitialized variables are searched for only in CMAKE_SOURCE_DIR and CMAKE_BINARY_DIR. This flag tells CMake to warn about other files as well.

--compile-no-warning-as-error¶: New in version 3.24.

Ignore target property COMPILE_WARNING_AS_ERROR and variable CMAKE_COMPILE_WARNING_AS_ERROR, preventing warnings from being treated as errors on compile.

--profiling-output=<path>¶: New in version 3.18.

Used in conjunction with --profiling-format to output to a given path.

--profiling-format=<file>¶

Enable the output of profiling data of CMake script in the given format.

This can aid performance analysis of CMake scripts executed. Third party applications should be used to process the output into human readable format.

Currently supported values are: google-trace Outputs in Google Trace Format, which can be parsed by the about:tracing tab of Google Chrome or using a plugin for a tool like Trace Compass.

--preset <preset>, --preset=<preset>¶

Reads a preset from <path-to-source>/CMakePresets.json and <path-to-source>/CMakeUserPresets.json. The preset may specify the generator and the build directory, and a list of variables and other arguments to pass to CMake. The current working directory must contain CMake preset files. The CMake GUI can also recognize CMakePresets.json and CMakeUserPresets.json files. For full details on these files, see cmake-presets(7).

The presets are read before all other command line options. The options specified by the preset (variables, generator, etc.) can all be overridden by manually specifying them on the command line. For example, if the preset sets a variable called MYVAR to 1, but the user sets it to 2 with a -D argument, the value 2 is preferred.

--list-presets[=<type>]¶: Lists the available presets of the specified <type>. Valid values for <type> are configure, build, test, package, or all. If <type> is omitted, configure is assumed. The current working directory must contain CMake preset files.

--debugger¶

Enables interactive debugging of the CMake language. CMake exposes a debugging interface on the pipe named by --debugger-pipe that conforms to the Debug Adapter Protocol specification with the following modifications.

The initialize response includes an additional field named cmakeVersion which specifies the version of CMake being debugged.

Debugger initialize response¶

{
  "cmakeVersion": {
    "major": 3,
    "minor": 27,
    "patch": 0,
    "full": "3.27.0"
  }
}

The members are:

major: An integer specifying the major version number.
minor: An integer specifying the minor version number.
patch: An integer specifying the patch version number.
full: A string specifying the full CMake version.

--debugger-pipe <pipe name>, --debugger-pipe=<pipe name>¶: Name of the pipe (on Windows) or domain socket (on Unix) to use for debugger communication.

--debugger-dap-log <log path>, --debugger-dap-log=<log path>¶: Logs all debugger communication to the specified file.

Build a Project¶

CMake provides a command-line signature to build an already-generated project binary tree:

cmake --build <dir>             [<options>] [-- <build-tool-options>]
cmake --build --preset <preset> [<options>] [-- <build-tool-options>]

This abstracts a native build tool's command-line interface with the following options:

--build <dir>¶: Project binary directory to be built. This is required (unless a preset is specified) and must be first.

--preset <preset>, --preset=<preset>¶: Use a build preset to specify build options. The project binary directory is inferred from the configurePreset key. The current working directory must contain CMake preset files. See preset for more details.

--list-presets¶: Lists the available build presets. The current working directory must contain CMake preset files.

-j [<jobs>], --parallel [<jobs>]¶

New in version 3.12.

The maximum number of concurrent processes to use when building. If <jobs> is omitted the native build tool's default number is used.

The CMAKE_BUILD_PARALLEL_LEVEL environment variable, if set, specifies a default parallel level when this option is not given.

Some native build tools always build in parallel. The use of <jobs> value of 1 can be used to limit to a single job.

-t <tgt>..., --target <tgt>...¶: Build <tgt> instead of the default target. Multiple targets may be given, separated by spaces.

--config <cfg>¶: For multi-configuration tools, choose configuration <cfg>.

--clean-first¶: Build target clean first, then build. (To clean only, use --target clean.)

--resolve-package-references=<value>¶

New in version 3.23.

Resolve remote package references from external package managers (e.g. NuGet) before build. When <value> is set to on (default), packages will be restored before building a target. When <value> is set to only, the packages will be restored, but no build will be performed. When <value> is set to off, no packages will be restored.

If the target does not define any package references, this option does nothing.

This setting can be specified in a build preset (using resolvePackageReferences). The preset setting will be ignored, if this command line option is specified.

If no command line parameter or preset option are provided, an environment- specific cache variable will be evaluated to decide, if package restoration should be performed.

When using the Visual Studio generator, package references are defined using the VS_PACKAGE_REFERENCES property. Package references are restored using NuGet. It can be disabled by setting the CMAKE_VS_NUGET_PACKAGE_RESTORE variable to OFF.

--use-stderr¶: Ignored. Behavior is default in CMake >= 3.0.

-v, --verbose¶

Enable verbose output - if supported - including the build commands to be executed.

This option can be omitted if VERBOSE environment variable or CMAKE_VERBOSE_MAKEFILE cached variable is set.

--¶: Pass remaining options to the native tool.

Run cmake --build with no options for quick help.

Install a Project¶

CMake provides a command-line signature to install an already-generated project binary tree:

cmake --install <dir> [<options>]

This may be used after building a project to run installation without using the generated build system or the native build tool. The options are:

--install <dir>¶: Project binary directory to install. This is required and must be first.

--config <cfg>¶: For multi-configuration generators, choose configuration <cfg>.

--component <comp>¶: Component-based install. Only install component <comp>.

--default-directory-permissions <permissions>¶: Default directory install permissions. Permissions in format <u=rwx,g=rx,o=rx>.

--prefix <prefix>¶: Override the installation prefix, CMAKE_INSTALL_PREFIX.

--strip¶: Strip before installing.

-v, --verbose¶

Enable verbose output.

This option can be omitted if VERBOSE environment variable is set.

Run cmake --install with no options for quick help.

Open a Project¶

cmake --open <dir>

Open the generated project in the associated application. This is only supported by some generators.

Run a Script¶

cmake [-D <var>=<value>]... -P <cmake-script-file> [-- <unparsed-options>...]

-D <var>=<value>¶: Define a variable for script mode.

-P <cmake-script-file>¶: Process the given cmake file as a script written in the CMake language. No configure or generate step is performed and the cache is not modified. If variables are defined using -D, this must be done before the -P argument.

Any options after -- are not parsed by CMake, but they are still included in the set of CMAKE_ARGV<n> variables passed to the script (including the -- itself).

Run a Command-Line Tool¶

CMake provides builtin command-line tools through the signature

cmake -E <command> [<options>]

-E [help]¶: Run cmake -E or cmake -E help for a summary of commands.

Available commands are:

capabilities¶

New in version 3.7.

Report cmake capabilities in JSON format. The output is a JSON object with the following keys:

version

A JSON object with version information. Keys are:

string: The full version string as displayed by cmake --version.
major: The major version number in integer form.
minor: The minor version number in integer form.
patch: The patch level in integer form.
suffix: The cmake version suffix string.
isDirty: A bool that is set if the cmake build is from a dirty tree.

generators

A list available generators. Each generator is a JSON object with the following keys:

name: A string containing the name of the generator.
toolsetSupport: true if the generator supports toolsets and false otherwise.
platformSupport: true if the generator supports platforms and false otherwise.
supportedPlatforms: New in version 3.21.

Optional member that may be present when the generator supports platform specification via CMAKE_GENERATOR_PLATFORM (-A ...). The value is a list of platforms known to be supported.
extraGenerators: A list of strings with all the Extra Generators compatible with the generator.

fileApi

Optional member that is present when the cmake-file-api(7) is available. The value is a JSON object with one member:

requests

A JSON array containing zero or more supported file-api requests. Each request is a JSON object with members:

kind: Specifies one of the supported Object Kinds.
version: A JSON array whose elements are each a JSON object containing major and minor members specifying non-negative integer version components.

serverMode

true if cmake supports server-mode and false otherwise. Always false since CMake 3.20.

tls

New in version 3.25.

true if TLS support is enabled and false otherwise.

debugger

New in version 3.27.

true if the --debugger mode is supported and false otherwise.

cat [--] <files>...¶

New in version 3.18.

Concatenate files and print on the standard output.

--¶: New in version 3.24.

Added support for the double dash argument --. This basic implementation of cat does not support any options, so using a option starting with - will result in an error. Use -- to indicate the end of options, in case a file starts with -.

chdir <dir> <cmd> [<arg>...]¶: Change the current working directory and run a command.

compare_files [--ignore-eol] <file1> <file2>¶

Check if <file1> is same as <file2>. If files are the same, then returns 0, if not it returns 1. In case of invalid arguments, it returns 2.

--ignore-eol¶: New in version 3.14.

The option implies line-wise comparison and ignores LF/CRLF differences.

copy <file>... <destination>, copy -t <destination> <file>...¶: Copy files to <destination> (either file or directory). If multiple files are specified, or if -t is specified, the <destination> must be directory and it must exist. If -t is not specified, the last argument is assumed to be the <destination>. Wildcards are not supported. copy does follow symlinks. That means it does not copy symlinks, but the files or directories it point to.

New in version 3.5: Support for multiple input files.

New in version 3.26: Support for -t argument.

copy_directory <dir>... <destination>¶: Copy content of <dir>... directories to <destination> directory. If <destination> directory does not exist it will be created. copy_directory does follow symlinks.

New in version 3.5: Support for multiple input directories.

New in version 3.15: The command now fails when the source directory does not exist. Previously it succeeded by creating an empty destination directory.

copy_directory_if_different <dir>... <destination>¶

New in version 3.26.

Copy changed content of <dir>... directories to <destination> directory. If <destination> directory does not exist it will be created.

copy_directory_if_different does follow symlinks. The command fails when the source directory does not exist.

copy_if_different <file>... <destination>¶: Copy files to <destination> (either file or directory) if they have changed. If multiple files are specified, the <destination> must be directory and it must exist. copy_if_different does follow symlinks.

New in version 3.5: Support for multiple input files.

create_symlink <old> <new>¶: Create a symbolic link <new> naming <old>.

New in version 3.13: Support for creating symlinks on Windows.

Note

Path to where <new> symbolic link will be created has to exist beforehand.

create_hardlink <old> <new>¶: New in version 3.19.

Create a hard link <new> naming <old>.

Note

Path to where <new> hard link will be created has to exist beforehand. <old> has to exist beforehand.

echo [<string>...]¶: Displays arguments as text.

echo_append [<string>...]¶: Displays arguments as text but no new line.

env [<options>] [--] <command> [<arg>...]¶

New in version 3.1.

Run command in a modified environment. Options are:

NAME=VALUE¶: Replaces the current value of NAME with VALUE.

--unset=NAME¶: Unsets the current value of NAME.

--modify ENVIRONMENT_MODIFICATION¶

New in version 3.25.

Apply a single ENVIRONMENT_MODIFICATION operation to the modified environment.

The NAME=VALUE and --unset=NAME options are equivalent to --modify NAME=set:VALUE and --modify NAME=unset:, respectively. Note that --modify NAME=reset: resets NAME to the value it had when cmake launched (or unsets it), not to the most recent NAME=VALUE option.

--¶: New in version 3.24.

Added support for the double dash argument --. Use -- to stop interpreting options/environment variables and treat the next argument as the command, even if it start with - or contains a =.

environment¶: Display the current environment variables.

false¶: New in version 3.16.

Do nothing, with an exit code of 1.

make_directory <dir>...¶: Create <dir> directories. If necessary, create parent directories too. If a directory already exists it will be silently ignored.

New in version 3.5: Support for multiple input directories.

md5sum <file>...¶

Create MD5 checksum of files in md5sum compatible format:

351abe79cd3800b38cdfb25d45015a15  file1.txt
052f86c15bbde68af55c7f7b340ab639  file2.txt

sha1sum <file>...¶

New in version 3.10.

Create SHA1 checksum of files in sha1sum compatible format:

4bb7932a29e6f73c97bb9272f2bdc393122f86e0  file1.txt
1df4c8f318665f9a5f2ed38f55adadb7ef9f559c  file2.txt

sha224sum <file>...¶

New in version 3.10.

Create SHA224 checksum of files in sha224sum compatible format:

b9b9346bc8437bbda630b0b7ddfc5ea9ca157546dbbf4c613192f930  file1.txt
6dfbe55f4d2edc5fe5c9197bca51ceaaf824e48eba0cc453088aee24  file2.txt

sha256sum <file>...¶

New in version 3.10.

Create SHA256 checksum of files in sha256sum compatible format:

76713b23615d31680afeb0e9efe94d47d3d4229191198bb46d7485f9cb191acc  file1.txt
15b682ead6c12dedb1baf91231e1e89cfc7974b3787c1e2e01b986bffadae0ea  file2.txt

sha384sum <file>...¶

New in version 3.10.

Create SHA384 checksum of files in sha384sum compatible format:

acc049fedc091a22f5f2ce39a43b9057fd93c910e9afd76a6411a28a8f2b8a12c73d7129e292f94fc0329c309df49434  file1.txt
668ddeb108710d271ee21c0f3acbd6a7517e2b78f9181c6a2ff3b8943af92b0195dcb7cce48aa3e17893173c0a39e23d  file2.txt

sha512sum <file>...¶

New in version 3.10.

Create SHA512 checksum of files in sha512sum compatible format:

2a78d7a6c5328cfb1467c63beac8ff21794213901eaadafd48e7800289afbc08e5fb3e86aa31116c945ee3d7bf2a6194489ec6101051083d1108defc8e1dba89  file1.txt
7a0b54896fe5e70cca6dd643ad6f672614b189bf26f8153061c4d219474b05dad08c4e729af9f4b009f1a1a280cb625454bf587c690f4617c27e3aebdf3b7a2d  file2.txt

remove [-f] <file>...¶

Deprecated since version 3.17.

Remove the file(s). The planned behavior was that if any of the listed files already do not exist, the command returns a non-zero exit code, but no message is logged. The -f option changes the behavior to return a zero exit code (i.e. success) in such situations instead. remove does not follow symlinks. That means it remove only symlinks and not files it point to.

The implementation was buggy and always returned 0. It cannot be fixed without breaking backwards compatibility. Use rm instead.

remove_directory <dir>...¶: Deprecated since version 3.17.

Remove <dir> directories and their contents. If a directory does not exist it will be silently ignored. Use rm instead.

New in version 3.15: Support for multiple directories.

New in version 3.16: If <dir> is a symlink to a directory, just the symlink will be removed.

rename <oldname> <newname>¶: Rename a file or directory (on one volume). If file with the <newname> name already exists, then it will be silently replaced.

rm [-rRf] [--] <file|dir>...¶: New in version 3.17.

Remove the files <file> or directories <dir>. Use -r or -R to remove directories and their contents recursively. If any of the listed files/directories do not exist, the command returns a non-zero exit code, but no message is logged. The -f option changes the behavior to return a zero exit code (i.e. success) in such situations instead. Use -- to stop interpreting options and treat all remaining arguments as paths, even if they start with -.

sleep <number>¶

New in version 3.0.

Sleep for <number> seconds. <number> may be a floating point number. A practical minimum is about 0.1 seconds due to overhead in starting/stopping CMake executable. This can be useful in a CMake script to insert a delay:

# Sleep for about 0.5 seconds
execute_process(COMMAND ${CMAKE_COMMAND} -E sleep 0.5)

tar [cxt][vf][zjJ] file.tar [<options>] [--] [<pathname>...]¶

Create or extract a tar or zip archive. Options are:

c¶: Create a new archive containing the specified files. If used, the <pathname>... argument is mandatory.

x¶: Extract to disk from the archive.

New in version 3.15: The <pathname>... argument could be used to extract only selected files or directories. When extracting selected files or directories, you must provide their exact names including the path, as printed by list (-t).

t¶: List archive contents.

New in version 3.15: The <pathname>... argument could be used to list only selected files or directories.

v¶: Produce verbose output.

z¶: Compress the resulting archive with gzip.

j¶: Compress the resulting archive with bzip2.

J¶: New in version 3.1.

Compress the resulting archive with XZ.

--zstd¶: New in version 3.15.

Compress the resulting archive with Zstandard.

--files-from=<file>¶: New in version 3.1.

Read file names from the given file, one per line. Blank lines are ignored. Lines may not start in - except for --add-file=<name> to add files whose names start in -.

--format=<format>¶: New in version 3.3.

Specify the format of the archive to be created. Supported formats are: 7zip, gnutar, pax, paxr (restricted pax, default), and zip.

--mtime=<date>¶: New in version 3.1.

Specify modification time recorded in tarball entries.

--touch¶: New in version 3.24.

Use current local timestamp instead of extracting file timestamps from the archive.

--¶: New in version 3.1.

Stop interpreting options and treat all remaining arguments as file names, even if they start with -.

New in version 3.1: LZMA (7zip) support.

New in version 3.15: The command now continues adding files to an archive even if some of the files are not readable. This behavior is more consistent with the classic tar tool. The command now also parses all flags, and if an invalid flag was provided, a warning is issued.

time <command> [<args>...]¶: Run <command> and display elapsed time (including overhead of CMake frontend).

New in version 3.5: The command now properly passes arguments with spaces or special characters through to the child process. This may break scripts that worked around the bug with their own extra quoting or escaping.

touch <file>...¶: Creates <file> if file do not exist. If <file> exists, it is changing <file> access and modification times.

touch_nocreate <file>...¶: Touch a file if it exists but do not create it. If a file does not exist it will be silently ignored.

true¶: New in version 3.16.

Do nothing, with an exit code of 0.

Windows-specific Command-Line Tools¶

The following cmake -E commands are available only on Windows:

delete_regv <key>¶: Delete Windows registry value.

env_vs8_wince <sdkname>¶: New in version 3.2.

Displays a batch file which sets the environment for the provided Windows CE SDK installed in VS2005.

env_vs9_wince <sdkname>¶: New in version 3.2.

Displays a batch file which sets the environment for the provided Windows CE SDK installed in VS2008.

write_regv <key> <value>¶: Write Windows registry value.

Run the Find-Package Tool¶

CMake provides a pkg-config like helper for Makefile-based projects:

cmake --find-package [<options>]

It searches a package using find_package() and prints the resulting flags to stdout. This can be used instead of pkg-config to find installed libraries in plain Makefile-based projects or in autoconf-based projects (via share/aclocal/cmake.m4).

Note

This mode is not well-supported due to some technical limitations. It is kept for compatibility but should not be used in new projects.

Run a Workflow Preset¶

New in version 3.25.

CMake Presets provides a way to execute multiple build steps in order:

cmake --workflow [<options>]

The options are:

--workflow¶: Select a Workflow Preset using one of the following options.

--preset <preset>, --preset=<preset>¶: Use a workflow preset to specify a workflow. The project binary directory is inferred from the initial configure preset. The current working directory must contain CMake preset files. See preset for more details.

--list-presets¶: Lists the available workflow presets. The current working directory must contain CMake preset files.

--fresh¶: Perform a fresh configuration of the build tree. This removes any existing CMakeCache.txt file and associated CMakeFiles/ directory, and recreates them from scratch.

View Help¶

To print selected pages from the CMake documentation, use

cmake --help[-<topic>]

with one of the following options:

-version [<file>], --version [<file>], /V [<file>]¶: Show program name/version banner and exit. The output is printed to a named <file> if given.

-h, -H, --help, -help, -usage, /?¶

Print usage information and exit.

Usage describes the basic command line interface and its options.

--help <keyword> [<file>]¶

Print help for one CMake keyword.

<keyword> can be a property, variable, command, policy, generator or module.

The relevant manual entry for <keyword> is printed in a human-readable text format. The output is printed to a named <file> if given.

Changed in version 3.28: Prior to CMake 3.28, this option supported command names only.

--help-full [<file>]¶

Print all help manuals and exit.

All manuals are printed in a human-readable text format. The output is printed to a named <file> if given.

--help-manual <man> [<file>]¶

Print one help manual and exit.

The specified manual is printed in a human-readable text format. The output is printed to a named <file> if given.

--help-manual-list [<file>]¶

List help manuals available and exit.

The list contains all manuals for which help may be obtained by using the --help-manual option followed by a manual name. The output is printed to a named <file> if given.

--help-command <cmd> [<file>]¶

Print help for one command and exit.

The cmake-commands(7) manual entry for <cmd> is printed in a human-readable text format. The output is printed to a named <file> if given.

--help-command-list [<file>]¶

List commands with help available and exit.

The list contains all commands for which help may be obtained by using the --help-command option followed by a command name. The output is printed to a named <file> if given.

--help-commands [<file>]¶

Print cmake-commands manual and exit.

The cmake-commands(7) manual is printed in a human-readable text format. The output is printed to a named <file> if given.

--help-module <mod> [<file>]¶

Print help for one module and exit.

The cmake-modules(7) manual entry for <mod> is printed in a human-readable text format. The output is printed to a named <file> if given.

--help-module-list [<file>]¶

List modules with help available and exit.

The list contains all modules for which help may be obtained by using the --help-module option followed by a module name. The output is printed to a named <file> if given.

--help-modules [<file>]¶

Print cmake-modules manual and exit.

The cmake-modules(7) manual is printed in a human-readable text format. The output is printed to a named <file> if given.

--help-policy <cmp> [<file>]¶

Print help for one policy and exit.

The cmake-policies(7) manual entry for <cmp> is printed in a human-readable text format. The output is printed to a named <file> if given.

--help-policy-list [<file>]¶

List policies with help available and exit.

The list contains all policies for which help may be obtained by using the --help-policy option followed by a policy name. The output is printed to a named <file> if given.

--help-policies [<file>]¶

Print cmake-policies manual and exit.

The cmake-policies(7) manual is printed in a human-readable text format. The output is printed to a named <file> if given.

--help-property <prop> [<file>]¶

Print help for one property and exit.

The cmake-properties(7) manual entries for <prop> are printed in a human-readable text format. The output is printed to a named <file> if given.

--help-property-list [<file>]¶

List properties with help available and exit.

The list contains all properties for which help may be obtained by using the --help-property option followed by a property name. The output is printed to a named <file> if given.

--help-properties [<file>]¶

Print cmake-properties manual and exit.

The cmake-properties(7) manual is printed in a human-readable text format. The output is printed to a named <file> if given.

--help-variable <var> [<file>]¶

Print help for one variable and exit.

The cmake-variables(7) manual entry for <var> is printed in a human-readable text format. The output is printed to a named <file> if given.

--help-variable-list [<file>]¶

List variables with help available and exit.

The list contains all variables for which help may be obtained by using the --help-variable option followed by a variable name. The output is printed to a named <file> if given.

--help-variables [<file>]¶

Print cmake-variables manual and exit.

The cmake-variables(7) manual is printed in a human-readable text format. The output is printed to a named <file> if given.

To view the presets available for a project, use

cmake <source-dir> --list-presets

Return Value (Exit Code)¶

Upon regular termination, the cmake executable returns the exit code 0.

If termination is caused by the command message(FATAL_ERROR), or another error condition, then a non-zero exit code is returned.

cmake(1)¶

Synopsis¶

Description¶

Introduction to CMake Buildsystems¶

Generate a Project Buildsystem¶

Options¶

Build a Project¶

Install a Project¶

Open a Project¶

Run a Script¶

Run a Command-Line Tool¶

Windows-specific Command-Line Tools¶

Run the Find-Package Tool¶

Run a Workflow Preset¶

View Help¶

Return Value (Exit Code)¶

See Also¶

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