Wait For Mountpoint

I have quite a few scripts running on my home server and they love writing on disk. They love it so much that, after reboot, they don't necessarily wait for mount points to appear - they just start writing. Unfortunately, such eagerness also means that my other scripts mounting ZFS might find directory already in use and give up.

What I needed was a way to check if mount point is already there before starting with write. The easiest approach for me was using mountpoint command.

TEST_PATH=/test/directory
while(true); do  # wait for mount point
    mountpoint "$TEST_PATH" >/dev/null
    if [[ $? != 0 ]]; then
        sleep 1
        continue
    fi
    break
done

Script fragment above will check if given directory has something mounted and, if not, wait for 1 more second. Once test succeeds, it will break out of the infinite loop and proceed with whatever follows.

Easy enough.