XDG Base Directory Specification
Various specifications specify files and file formats. This specification defines where these files should be looked for by defining one or more base directories relative to which files should be located.
There is a single base directory relative to which user-specific data files should be written. This directory is defined by the environment variable $XDG_DATA_HOME.
There is a single base directory relative to which user-specific configuration files should be written. This directory is defined by the environment variable $XDG_CONFIG_HOME.
There is a single base directory relative to which user-specific state data should be written. This directory is defined by the environment variable $XDG_STATE_HOME.
There is a single base directory relative to which user-specific executable files may be written.
