--- short-description: Installing targets ... # Installing Invoked via the [following command](Commands.md#install) *(available since 0.47.0)*: ```sh meson install ``` or alternatively (on older Meson versions with `ninja` backend): ```sh ninja install ``` By default Meson will not install anything. Build targets can be installed by tagging them as installable in the definition. ```meson project('install', 'c') shared_library('mylib', 'libfile.c', install : true) ``` There is usually no need to specify install paths or the like. Meson will automatically install it to the standards-conforming location. In this particular case the executable is installed to the `bin` subdirectory of the install prefix. However if you wish to override the install dir, you can do that with the `install_dir` argument. ```meson executable('prog', 'prog.c', install : true, install_dir : 'my/special/dir') ``` Other install commands are the following. ```meson install_headers('header.h', subdir : 'projname') # -> include/projname/header.h install_man('foo.1') # -> share/man/man1/foo.1 install_data('datafile.dat', install_dir : get_option('datadir') / 'progname') # -> share/progname/datafile.dat ``` `install_data()` supports rename of the file *since 0.46.0*. ```meson # file.txt -> {datadir}/{projectname}/new-name.txt install_data('file.txt', rename : 'new-name.txt') # file1.txt -> share/myapp/dir1/data.txt # file2.txt -> share/myapp/dir2/data.txt install_data(['file1.txt', 'file2.txt'], rename : ['dir1/data.txt', 'dir2/data.txt'], install_dir : 'share/myapp') ``` Sometimes you want to copy an entire subtree directly. For this use case there is the `install_subdir` command, which can be used like this. ```meson install_subdir('mydir', install_dir : 'include') # mydir subtree -> include/mydir ``` Most of the time you want to install files relative to the install prefix. Sometimes you need to go outside of the prefix (such as writing files to `/etc` instead of `/usr/etc`. This can be accomplished by giving an absolute install path. ```meson install_data(sources : 'foo.dat', install_dir : '/etc') # -> /etc/foo.dat ``` ## Custom install script Sometimes you need to do more than just install basic targets. Meson makes this easy by allowing you to specify a custom script to execute at install time. As an example, here is a script that generates an empty file in a custom directory. ```bash #!/bin/sh mkdir "${DESTDIR}/${MESON_INSTALL_PREFIX}/mydir" touch "${DESTDIR}/${MESON_INSTALL_PREFIX}/mydir/file.dat" ``` As you can see, Meson sets up some environment variables to help you write your script (`DESTDIR` is not set by Meson, it is inherited from the outside environment). In addition to the install prefix, Meson also sets the variables `MESON_SOURCE_ROOT` and `MESON_BUILD_ROOT`. Telling Meson to run this script at install time is a one-liner. ```meson meson.add_install_script('myscript.sh') ``` The argument is the name of the script file relative to the current subdirectory. ## DESTDIR support Sometimes you need to install to a different directory than the install prefix. This is most common when building rpm or deb packages. This is done with the `DESTDIR` environment variable and it is used just like with other build systems: ```console $ DESTDIR=/path/to/staging/area meson install ``` Since *0.57.0* `--destdir` argument can be used instead of environment. In that case Meson will set `DESTDIR` into environment when running install scripts. Since *0.60.0* `DESTDIR` and `--destdir` can be a path relative to build directory. An absolute path will be set into environment when executing scripts. ## Custom install behaviour Installation behaviour can be further customized using additional arguments. For example, if you wish to install the current setup without rebuilding the code (which the default install target always does) and only installing those files that have changed, you would run this command in the build tree: ```console $ meson install --no-rebuild --only-changed ``` ## Installation tags *Since 0.60.0* It is possible to install only a subset of the installable files using `meson install --tags tag1,tag2` command line. When `--tags` is specified, only files that have been tagged with one of the tags are going to be installed. This is intended to be used by packagers (e.g. distributions) who typically want to split `libfoo`, `libfoo-dev` and `libfoo-doc` packages. Instead of duplicating the list of installed files per category in each packaging system, it can be maintained in a single place, directly in upstream `meson.build` files. Meson sets predefined tags on some files. More tags are likely to be added over time, please help extending the list of well known categories. - `devel`: * `static_library()`, * `install_headers()`, * `pkgconfig.generate()`, * `gnome.generate_gir()` - `.gir` file, * Files installed into `libdir` and with `.a` or `.pc` extension, * File installed into `includedir`. - `runtime`: * `executable()`, * `shared_library()`, * `shared_module()`, * `jar()`, * Files installed into `bindir`. * Files installed into `libdir` and with `.so` or `.dll` extension. - `python-runtime`: * `python.install_sources()`. - `man`: * `install_man()`. - `doc`: * `gnome.gtkdoc()`, * `gnome.yelp()`, * `hotdoc.generate_doc()`. - `i18n`: * `i18n.gettext()`, * `qt.compile_translations()`, * Files installed into `localedir`. - `typelib`: * `gnome.generate_gir()` - `.typelib` file. Custom installation tag can be set using the `install_tag` keyword argument on various functions such as `custom_target()`, `configure_file()`, `install_subdir()` and `install_data()`. See their respective documentation in the reference manual for details. It is recommended to use one of the predefined tags above when possible. Installable files that have not been tagged either automatically by Meson, or manually using `install_tag` keyword argument won't be installed when `--tags` is used. They are reported at the end of `/meson-logs/meson-log.txt`, it is recommended to add missing `install_tag` to have a tag on each installable files.