---

title: Change default applications on Linux from terminal

url: change-default-applications-on-linux-from-terminal.html

date: 2026-01-15T16:13:13+02:00

type: post

draft: false

tags: []

---

Changing default applications is done with command `xdg-mime`. This is a

command line tool for querying information about file type handling and adding

descriptions for new file types. Make sure you have this program installed.

Application will use `.desktop` files to associate applications with specific

types.

## Location and structure of `.desktop` files

```sh

ls /usr/share/applications

ls ~/.local/share/applications

```

You can add your own `.desktop` files to `~/.local/share/applications`.

An example of `.desktop` file for Brave browser located in

`~/.local/share/applications/brave.desktop`.

```ini

[Desktop Entry]

Exec=/home/m/Applications/brave

Type=Application

Categories=Applications

Name=Brave Browser

```

## Query current associations

You can query specific types with `xdg-mime`.

```sh

xdg-mime query default text/plain

xdg-mime query default text/html

xdg-mime query default x-scheme-handler/http

xdg-mime query default x-scheme-handler/https

xdg-mime query default inode/directory

```

Or you can look at the files containing this data.

```sh

less ~/.config/mimeapps.list

less /usr/share/applications/mimeapps.list

```

## Set default application

```sh

# Set Brave as default browser.

xdg-mime default brave.desktop x-scheme-handler/http

xdg-mime default brave.desktop x-scheme-handler/https

# Set Thunar as default file explorer.

xdg-mime default thunar.desktop inode/directory

# Set Mousepad as default txt editor.

xdg-mime default mousepad.desktop text/plain

```

## Interfacing with C

This simple example lists all registered types. But you can see where this can

go. This could be turned into ncurses CLI application that is used for setting

and changing default applications.

```c

#include <gio/gio.h>

int main(void) {

    GList *types = g_content_types_get_registered();

    for (GList *l=types; l!=NULL; l=l->next) {

        g_print("%s\n", (char *)l->data);

    }

    g_list_free_full(types, g_free);

    return 0;

}

```

Compile with `clang -o main main.c $(pkg-config --cflags --libs gio-2.0)`.

## Reading material

- https://wiki.archlinux.org/title/XDG_MIME_Applications

- https://commandmasters.com/commands/xdg-mime-linux/

- https://noman.sh/en/pages/xdg-mime

- https://linux.die.net/man/1/xdg-mime

- https://wiki.archlinux.org/title/XDG_MIME_Applications

- https://gnome.pages.gitlab.gnome.org/libsoup/gio/

- https://docs.gtk.org/gio/