Xdg-open

xdg-open is a desktop-independent tool for configuring the default applications of a user. Many applications invoke the xdg-open command internally.

Inside a desktop environment (e.g. GNOME, KDE, Xfce, etc.), xdg-open simply passes the arguments to that desktop environment's file-opener application (gvfs-open, kde-open, or exo-open, respectively), which means that the associations are left up to the desktop environment. When no desktop environment is detected (for example when one runs a standalone window manager, e.g. Openbox), xdg-open will use its own configuration files.

Installation

xdg-open is part of the xdg-utils package available in the official repositories. xdg-open is for use inside a desktop session only. It is not recommended to use xdg-open as root.

Configuration

The config file

xdg-open uses configuration files located at $XDG_DATA_HOME/applications/mimeapps.list (for a single user; $XDG_DATA_HOME defaults to ~/.local/share) and /usr/share/applications/defaults.list (system wide). Its format is as follows:

[Default Applications]
mimetype=desktopfile1;desktopfile2...

For example:

[Default Applications]
text/html=firefox.desktop
inode/directory=kde4-dolphin.desktop;Thunar.desktop;nautilus.desktop

The best way to look up the MIME type is to read the MimeTypes list in your application's .desktop file (see Desktop Entries for details).

Some tools are available to edit the configuration files:

xdg-mime

• To get mime type of photo.jpg:

$ xdg-mime query filetype photo.jpg

photo.jpg
    image/jpeg

• To get default .desktop file starter for image/jpeg mime type:

$ xdg-mime query default image/jpeg

gpicview.desktop;

• To make Thunar the default file-browser, i.e. the default application for opening folders:

$ xdg-mime default Thunar.desktop inode/directory

• To use xpdf as the default PDF viewer:

$ xdg-mime default xpdf.desktop application/pdf

Previous command should create an entry in your local MIME database:

~/.local/share/applications/defaults.list

[Default Applications]
application/pdf=xpdf.desktop

Setting default browser for xdg-open

This can be tricky to find, so to save you some work:

 $ xdg-mime default firefox.desktop x-scheme-handler/http
 $ xdg-mime default firefox.desktop x-scheme-handler/https

Drop-in replacements and useful tools

xdg-open replacements

Name/Package	Description	Based on	Configuration file
busking-gitAUR	A simple, regex-based xdg-open replacement.	perl-file-mimeinfo	custom
exproAUR	Opens objects in associated applications by matching regular expressions against object name or MIME-type.	file (but alternatives can be configured)	custom
linopenAUR	An intelligent and suckless replacement for xdg-open.	file	custom
mimeoAUR	Open files by MIME-type or file name using regular expressions. It can be used on its own or through xdg-utils-mimeoAUR.	file	standard mimeapps.list or defaults.list; custom is optional
mimi-gitAUR	A working replacement for xdg-open.	file	custom

run-mailcap

The .mailcap file format used by the mutt mail program is way easier to read and write. The run-mailcap^AUR package from the AUR provides a executable that could be easily symlinked to /usr/bin/xdg-open, but that parser is unable to handle directories or links. The simplest solution would be to install mimeo from the AUR too and create a /usr/bin/xdg-open with the following content:

#!/bin/sh
run-mailcap $1 || mimeo $1

Then use the defaults.list at ~/.local/share/applications/ to associate URLs and folders with applications and the .mailcap file for normal mimetypes.

mimetype

mimetype in perl-file-mimeinfo package can display some mimetype-related information about a file.

For example:

$ mimetype file.ext

returns the mimetype of a file,

$ mimetype -d file.extension

returns a description of that mimetype.

Environment variables

Some environment variables, such as BROWSER, DE, and DESKTOP_SESSION, will change the behaviour of the default xdg-open. See Environment Variables for more information.

See also

• Default Applications - Desktop-specific instructions/overview of alternatives to xdg-open
• Environment Variables