Unmount Using Regular Expression
This is a quick aid to unmounting all --bind mounts in chroot configurations. It solves an issue where scanning a file system for used/free space can end up examining a folder twice or more - which then reports incorrect usage and takes a lot longer.
Set REGEXP to the expression to match.
REGEXP=".* on \(.*chroots.*\) type .*"; \ mount | while read mountpoint; do \ mpath=$(expr match "$mountpoint" "$REGEXP"); \ if [ ! -z "$mpath" ]; then echo "umount $mpath"; sudo umount $mpath; fi; \ done