get_filename_component — CMake 4.3.4 Documentation

# get_filename_component

Get a specific component of a full filename.

Changed in version 3.20: This command has been superseded by the `cmake_path()` command, except for `REALPATH`, which is now offered by `file(REAL_PATH)`, and `PROGRAM`, now available in `separate_arguments(PROGRAM)`.

Changed in version 3.24: The undocumented feature offering the capability to query the `Windows` registry is superseded by the `cmake_host_system_information(QUERY WINDOWS_REGISTRY)` command.

    get_filename_component(<var> <FileName> <mode> [CACHE])

Sets `<var>` to a component of `<FileName>`, where `<mode>` is one of:

- `DIRECTORY` - directory without file name.

- `NAME` - file name without directory.

- `EXT` - file name longest extension (`.b.c` from `d/a.b.c`).

- `NAME_WE` - file name with neither the directory nor the longest extension.

- `LAST_EXT` - file name last extension (`.c` from `d/a.b.c`).

- `NAME_WLE` - file name with neither the directory nor the last extension.

- `PATH` - legacy alias for `DIRECTORY` (use for CMake <= 2.8.11).

Added in version 3.14: Added the `LAST_EXT` and `NAME_WLE` modes.

Paths are returned with forward slashes and have no trailing slashes. If the optional `CACHE` argument is specified, the result variable is added to the cache.

    get_filename_component(<var> <FileName> <mode> [BASE_DIR <dir>] [CACHE])

Added in version 3.4.

Sets `<var>` to the absolute path of `<FileName>`, where `<mode>` is one of:

- `ABSOLUTE` - full path to file.

- `REALPATH` - full path to existing file with symlinks resolved.

If the provided `<FileName>` is a relative path, it is evaluated relative to the given base directory `<dir>`. If no base directory is provided, the default base directory will be `CMAKE_CURRENT_SOURCE_DIR`.

Paths are returned with forward slashes and have no trailing slashes. If the optional `CACHE` argument is specified, the result variable is added to the cache.

    get_filename_component(<var> <FileName> PROGRAM [PROGRAM_ARGS <arg_var>] [CACHE])

The program in `<FileName>` will be found in the system search path or left as a full path. If `PROGRAM_ARGS` is present with `PROGRAM`, then any command-line arguments present in the `<FileName>` string are split from the program name and stored in `<arg_var>`. This is used to separate a program name from its arguments in a command line string.

## See Also

- `cmake_path()`