xdg-mime command_examples
xdg-mime – command line tool for querying information about file type handling and adding descriptions for new file types
xdg-mime query filetype /tmp/foobar.png
Prints the MIME type of the file /tmp/foobar.png, in this case image/png
xdg-mime query default image/png
Prints the .desktop filename of the application which is registered to open PNG files.
xdg-mime install shinythings-shiny.xml
Adds a file type description for “shiny”-files. “shinythings-” is used as the vendor prefix. The file type description could look as follows.
shinythings-shiny.xml:
Shiny new file type
An icon for this new file type must also be installed, for example with:
xdg-icon-resource install --context mimetypes --size 64 shiny-file-icon.png text-x-shiny