Package xdg provides an implementation of the XDG Base Directory Specification.

On initialization, the following package variables are set to their recommended values, by reading the corresponding environment variables and falling back to specification defaults if necessary.

ConfigHome      // user configuration base directory, e.g. ~/.config
DataHome        // user data files base directory, e.g. ~/.local/share
CacheHome       // user cache files base directory, e.g. ~/.cache
RuntimeDir      // user runtime files base directory, e.g. /run/user/1000
ConfigDirs      // global configuration directories, e.g. /etc/xdg
DataDirs        // global data files directories, e.g. /usr/local/share
AllConfigDirs   // user and global configuration directories
AllDataDirs     // user and global data directories

Initialization happens automatically, but can also be explicitely started with the Init function. If no valid path can be constructed, the variable is left blank or empty. If one of the required paths is blank or empty, the program should fail. These variables should be treated as read-only; change them only if you know what you are doing.

The package has four classes of functions, which should suffice for most needs:

User*           // construct a valid path for user (config|data|...) files
Find*           // find existing (config|data|...) files
Merge*          // execute a function on each found (config|data) file
Open*           // open or create a user (config|data|...) file

Only the Open* functions may alter the filesystem in any way: this is restricted to creating XDG user base directories and files therein. Directories in ConfigDirs and DataDirs are not modified.

The XDG Base Directory Specification, henceforth “the specification”, defines several types of files: configuration, data, cache, and runtime files. The specification can be found at:

http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html

Configuration files are read from ConfigHome and from ConfigDirs; they are only written in ConfigHome.

ConfigHome 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. If $XDG_CONFIG_HOME is not set, the default $HOME/.config is used.

ConfigDirs is a set of preference ordered base directories relative to which configuration files should be searched. This set of directories is defined by the environment variable $XDG_CONFIG_DIRS. The directories in $XDG_CONFIG_DIRS should be seperated with a colon :. If $XDG_CONFIG_DIRS is not set, the default /etc/xdg is used.

ConfigHomeDirs combines ConfigHome and ConfigDirs into one preference ordered set of directories.

Data files are read from DataHome and from DataDirs; they are only written in DataHome.

DataHome 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. If $XDG_DATA_HOME is not set, the default $HOME/.local/share is used.

DataDirs is a set of preference ordered base directories relative to which data files should be searched. This set of directories is defined by the environment variable $XDG_DATA_DIRS. If $XDG_CONFIG_DIRS is not set, the default /usr/local/share:/usr/share is used.

CacheHome is a single base directory relative to which user-specific non-essential (cached) data should be written. This directory is defined by the environment variable $XDG_CACHE_HOME. If $XDG_CACHE_HOME is not set, the default $HOME/.cache is used.

RuntimeDir is a single base directory relative to which user-specific runtime files and other file objects should be placed. This directory is defined by the environment variable $XDG_RUNTIME_DIR. If $XDG_RUNTIME_DIR is not set, the following method is used to find an appropriate directory:

path.Join(os.TempDir(), fmt.Sprintf("xdg-%d", os.Getuid()))

This usually results in paths such as /tmp/xdg-1000. Normally, we expect something along the lines of /run/user/1000.

In this implementation, we assume that the system takes care of removing the XDG runtime directory at shutdown.

For more information, see the documentation! :-) This package is licensed under the MIT license. This package takes much inspiration from adrg/xdg. Many Thanks.