XDG user directories

From freedesktop.org:

xdg-user-dirs is a tool to help manage "well known" user directories like the desktop folder and the music folder. It also handles localization (i.e. translation) of the filenames.

The way it works is that xdg-user-dirs-update(1) is run very early in the login phase. This program reads a configuration file, and a set of default directories. It then creates localized versions of these directories in the user home directory and sets up a configuration file in $XDG_CONFIG_HOME/user-dirs.dirs (XDG_CONFIG_HOME defaults to ~/.config) that applications can read to find these directories.

Most file managers indicate XDG user directories with special icons.

Installation

Install xdg-user-dirs.

Note: Some desktop environments might have it installed already, e.g. GNOME.

Creating default directories

Creating a full suite of localized default user directories within the $HOME directory can be done automatically by running:

$ xdg-user-dirs-update

Tip: To force the creation of English-named directories, LC_ALL=C.UTF-8 xdg-user-dirs-update --force can be used.

When executed, it will also automatically:

Create a local ~/.config/user-dirs.dirs configuration file: used by applications to find and use home directories specific to an account.
Create a local ~/.config/user-dirs.locale configuration file: used to set the language according to the locale in use.

The user service xdg-user-dirs-update.service will also be installed and enabled by default, in order to keep your directories up to date by running this command at the beginning of each login session.

Creating custom directories

Both the local ~/.config/user-dirs.dirs and global /etc/xdg/user-dirs.defaults configuration files use the following environmental variable format to point to user directories: XDG_DIRNAME_DIR="$HOME/directory_name" An example configuration file may likely look like this (these are all the template directories):

~/.config/user-dirs.dirs

XDG_DESKTOP_DIR="$HOME/Desktop"
XDG_DOCUMENTS_DIR="$HOME/Documents"
XDG_DOWNLOAD_DIR="$HOME/Downloads"
XDG_MUSIC_DIR="$HOME/Music"
XDG_PICTURES_DIR="$HOME/Pictures"
XDG_PUBLICSHARE_DIR="$HOME/Public"
XDG_TEMPLATES_DIR="$HOME/Templates"
XDG_VIDEOS_DIR="$HOME/Videos"

As xdg-user-dirs will source the local configuration file to point to the appropriate user directories, it is therefore possible to specify custom folders. For example, if a custom folder for the XDG_DOWNLOAD_DIR variable has named $HOME/Internet in ~/.config/user-dirs.dirs any application that uses this variable will use this directory.

Note: Like with many configuration files, local settings override global settings. It will also be necessary to create any new custom directories.

Alternatively, it is also possible to specify custom folders using the command line. For example, the following command will produce the same results as the above configuration file edit:

$ xdg-user-dirs-update --set DOWNLOAD ~/Internet

Querying configured directories

Once set, any user directory can be viewed with xdg-user-dirs. For example, the following command will show the location of the Templates directory, which of course corresponds to the XDG_TEMPLATES_DIR variable in the local configuration file:

$ xdg-user-dir TEMPLATES

Warning: xdg-user-dir should not receive its argument from unchecked input, since it simply passes it to eval without performing any sanity checks, in a line that looks like this:

eval echo \${XDG_${1}_DIR:-$HOME}

This means that xdg-user-dir facilitates arbitrary code execution from unsanitized input. Unless this unsafe implementation is fixed upstream, xdg-user-dir should only ever be used with a hard-coded or strictly audited argument.