The query option is for use inside a desktop session only. It is not recommended to use xdg-mime query as root.
The following queries are supported:
query filetype FILE: Returns the file type of FILE in the form of a MIME type.
query default mimetype: Returns the default application that the desktop environment uses for opening files of type mimetype. The default application is identified by its *.desktop file.
application is the desktop file id of the application and has the form vendor-name.desktop application must already be installed in the desktop menu before it can be made the default handler. The aplication's desktop file must list support for all the MIME types that it wishes to be the default handler for.
Requests to make an application a default handler may be subject to system policy or approval by the end-user. xdg-mime query can be used to verify whether an application is the actual default handler for a specific file type.
The default option is for use inside a desktop session only. It is not recommended to use xdg-mime default as root.
The default is to use system mode when called by root and to use user mode when called by a non-root user.
A vendor prefix consists of alpha characters ([a-zA-Z]) and is terminated with a dash ("-"). Companies and organizations are encouraged to use a word or phrase, preferably the organizations name, for which they hold a trademark as their vendor prefix. The purpose of the vendor prefix is to prevent name conflicts.
xdg-mime honours the following environment variables:
An exit code of 0 indicates success while a non-zero exit code indicates failure. The following failure codes can be returned:
xdg-icon-resource(1), xdg-desktop-menu(1)
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 folows.
shinythings-shiny.xml: <?xml version="1.0"?> <mime-info xmlns='http://www.freedesktop.org/standards/shared-mime-info'> <mime-type type="text/x-shiny"> <comment>Shiny new file type</comment> <glob pattern="*.shiny"/> <glob pattern="*.shi"/> </mime-type> </mime-info>
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