GNUInstallDirs

Define GNU standard installation directories

Provides install directory variables as defined by the GNU Coding Standards.

Result Variables

Inclusion of this module defines the following variables:

CMAKE_INSTALL_<dir>

Destination for files of a given type. This value may be passed to the DESTINATION options of install() commands for the corresponding file type. It should be a path relative to the installation prefix so that it can be converted to an absolute path in a relocatable way.

While absolute paths are allowed, they are not recommended as they do not work with the cmake --install command's --prefix option, or with the cpack installer generators. In particular, there is no need to make paths absolute by prepending CMAKE_INSTALL_PREFIX; this prefix is used by default if the DESTINATION is a relative path.

CMAKE_INSTALL_FULL_<dir>

The absolute path generated from the corresponding CMAKE_INSTALL_<dir> value. If the value is not already an absolute path, an absolute path is constructed typically by prepending the value of the CMAKE_INSTALL_PREFIX variable. However, there are some special cases as documented below.

These variables shouldn't be used in install() commands as they do not work with the cmake --install command's --prefix option, or with the cpack installer generators.

where <dir> is one of:

BINDIR

user executables (bin)

SBINDIR

system admin executables (sbin)

LIBEXECDIR

program executables (libexec)

SYSCONFDIR

read-only single-machine data (etc)

SHAREDSTATEDIR

modifiable architecture-independent data (com)

LOCALSTATEDIR

modifiable single-machine data (var)

RUNSTATEDIR

Added in version 3.9: run-time variable data (LOCALSTATEDIR/run)

LIBDIR

object code libraries (lib or lib64)

On Debian, this may be lib/<multiarch-tuple> when CMAKE_INSTALL_PREFIX is /usr.

INCLUDEDIR

C header files (include)

OLDINCLUDEDIR

C header files for non-gcc (/usr/include)

DATAROOTDIR

read-only architecture-independent data root (share)

DATADIR

read-only architecture-independent data (DATAROOTDIR)

INFODIR

info documentation (DATAROOTDIR/info)

LOCALEDIR

locale-dependent data (DATAROOTDIR/locale)

MANDIR

man documentation (DATAROOTDIR/man)

DOCDIR

documentation root (DATAROOTDIR/doc/PROJECT_NAME)

If the includer does not define a value the above-shown default will be used and the value will appear in the cache for editing by the user.

Special Cases

The following values of CMAKE_INSTALL_PREFIX are special:

/

For <dir> other than the SYSCONFDIR, LOCALSTATEDIR and RUNSTATEDIR, the value of CMAKE_INSTALL_<dir> is prefixed with usr/ if it is not user-specified as an absolute path. For example, the INCLUDEDIR value include becomes usr/include. This is required by the GNU Coding Standards, which state:

When building the complete GNU system, the prefix will be empty and /usr will be a symbolic link to /.

/usr

For <dir> equal to SYSCONFDIR, LOCALSTATEDIR or RUNSTATEDIR, the CMAKE_INSTALL_FULL_<dir> is computed by prepending just / to the value of CMAKE_INSTALL_<dir> if it is not user-specified as an absolute path. For example, the SYSCONFDIR value etc becomes /etc. This is required by the GNU Coding Standards.

/opt/...

For <dir> equal to SYSCONFDIR, LOCALSTATEDIR or RUNSTATEDIR, the CMAKE_INSTALL_FULL_<dir> is computed by appending the prefix to the value of CMAKE_INSTALL_<dir> if it is not user-specified as an absolute path. For example, the SYSCONFDIR value etc becomes /etc/opt/.... This is defined by the Filesystem Hierarchy Standard.

This behavior does not apply to paths under /opt/homebrew/....

Macros

GNUInstallDirs_get_absolute_install_dir

GNUInstallDirs_get_absolute_install_dir(absvar var dirname)

Added in version 3.7.

Set the given variable absvar to the absolute path contained within the variable var. This is to allow the computation of an absolute path, accounting for all the special cases documented above. While this macro is used to compute the various CMAKE_INSTALL_FULL_<dir> variables, it is exposed publicly to allow users who create additional path variables to also compute absolute paths where necessary, using the same logic. dirname is the directory name to get, e.g. BINDIR.

Changed in version 3.20: Added the <dirname> parameter. Previous versions of CMake passed this value through the variable ${dir}.