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Changed in version 3.20: This command has been superseded by the `cmake_path()` command, except for `REALPATH`, which is now offered by `file(REAL_PATH)`, and `PROGRAM`, now available in `separate_arguments(PROGRAM)`.

Changed in version 3.24: The undocumented feature offering the capability to query the `Windows` registry is superseded by cmake_host_system_information(QUERY WINDOWS_REGISTRY) command.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