Mountpoint checks if the directory is a mountpoint.
Be quiet - don't print anything.
Print major/minor device number of the filesystem on stdout.
Print major/minor device number of the blockdevice on stdout.
Zero if the directory is a mountpoint, non-zero if not.
Symbolic links are not followed, except when the -x option is
used. To force following symlinks, add a trailing slash to the
path of the directory.
The name of the command is misleading when the -x option is used,
but the option is useful for comparing if a directory and a device
match up, and there is no other command that can print the info easily.