How do I detect that a jump drive is mounted?

[Cameron Hutchison]

Knute Johnson <knute2009 at knutejohnson.com> writes:

>I've got a jump drive that I use to back up some files at night.  Is 
>there a simple way in a script that I can check to see that the drive is 
>mounted?

The file /etc/mtab contains a list of the mounted filesystems. This is
maintained by the mount(8) command. This is the traditional Unix file
containing the mounted filesystems.

The file /proc/mounts also contains a list of the mounted filesystems,
but as the kernel knows it, so it is probably more comprehensive than
/etc/mtab. This is a Linux-specific file.

Using grep over either of these should tell you what you want to know.

If your jump drive is mounted on /media/backup then you could use
something like this:

if ! grep -qs " /media/backup " /proc/mounts ; then
	echo "Jump drive not mounted" >&2
	exit 1
fi

in your script should ensure that there is something mounted on your
backup mount point.

Note the spaces around the mount point - this ensures you dont match
something like /foo/media/backup, or /media/backup/foo.