xdg-mime

Query and manage MIME types according to the XDG standard. More information: https://portland.freedesktop.org/doc/xdg-mime.html.

• Display the MIME type of a file:
  xdg-mime query filetype {{path/to/file}}
• Display the default application for opening PNGs:
  xdg-mime query default {{image/png}}
• Display the default application for opening a specific file:
  xdg-mime query default $(xdg-mime query filetype {{path/to/file}})
• Set imv as the default application for opening PNG and JPEG images:
  xdg-mime default {{imv.desktop}} {{image/png}} {{image/jpeg}}