How to use the command 'xdg-mime' (with examples)

xdg-mime is a command-line tool that enables users to query and manage MIME types according to the XDG standard. MIME types are a way of identifying the format of a file, helping systems determine how to handle files and launch appropriate applications. The tool can be used to display a file’s MIME type, query the default application for a specific MIME type, and set default applications. Understanding and handling MIME types is essential for smooth file operations and automation in desktop environments.

Use case 1: Display the MIME type of a file

Code:

xdg-mime query filetype path/to/file

Motivation: Determining the MIME type of a file is important when you need to understand how a system interprets the format. For instance, if you’re developing a software application or modifying file associations, knowing the MIME type ensures that you handle files more effectively, leveraging features or avoiding compatibility problems with applications that rely on MIME types.

Explanation:

• xdg-mime: Invokes the command-line tool to access MIME type functionalities.
• query: The subcommand used to obtain information about MIME types.
• filetype: Specifies that you want to determine the MIME type of a specified file.
• path/to/file: Represents the path to the file whose MIME type you’re querying. It can be replaced with the actual file path.

Example Output:

image/png

This output suggests that the file is a PNG image, and applications that open image files will likely handle it correctly.

Use case 2: Display the default application for opening PNGs

Code:

xdg-mime query default image/png

Motivation: Knowing the default application for a given MIME type is useful when dealing with files of specific formats. This is particularly beneficial if you’re trying to standardize workflows or configure application preferences for teams or across multiple devices.

Explanation:

• xdg-mime: The tool used to interact with MIME types.
• query: Indicates that you’re seeking information from the MIME system.
• default: Specifies that you want to identify the default application for a particular MIME type.
• image/png: The MIME type for which the default application is being queried.

Example Output:

eog.desktop

This signals that the Eye of GNOME (eog) is the default application for opening PNG files. Users can alter this setting if they prefer another application.

Use case 3: Display the default application for opening a specific file

Code:

xdg-mime query default $(xdg-mime query filetype path/to/file)

Motivation: Sometimes, you may need to confirm which application will open a specific file, especially if your work involves frequently handling files with various formats. This command aids in ensuring that files are opened with the correct default application, reducing user frustration and improving operational efficiency.

Explanation:

• xdg-mime: The command-line tool for managing MIME types.
• query default: Commands to identify the default application set for a particular MIME type.
• $(xdg-mime query filetype path/to/file): A nested command that first determines the MIME type of the file at path/to/file and then retrieves the default application associated with that MIME type.

Example Output:

vlc.desktop

Indicating VLC media player is set as the default for the specific file, likely a media format handled by VLC.

Use case 4: Set ‘imv’ as the default application for opening PNG and JPEG images

Code:

xdg-mime default imv.desktop image/png image/jpeg

Motivation: Changing the default application for certain file types is key when users find a different application more suitable for their needs. Switching defaults can optimize performance, enhance user experience, or provide additional functionalities that are better offered by a chosen application.

Explanation:

• xdg-mime: The tool enabling MIME type settings to be queried and changed.
• default: A command for setting the default application for specified MIME types.
• imv.desktop: The desktop entry (application identifier) for ‘imv’, an image viewer that the user prefers for opening image files.
• image/png image/jpeg: The MIME types for which ‘imv’ is being set as the default application, covering both PNG and JPEG image formats.

Example Output: Though there might be no immediate terminal output after execution, the result ensures that files with types image/png and image/jpeg will now open with ‘imv’ by default.

Conclusion:

Understanding how to use xdg-mime effectively allows for better management of file handling on Unix-like systems. Whether you’re an individual user or an administrator managing multiple systems, being able to query and set default applications for different file types helps create a smoother, more customized user experience and can significantly enhance productivity.