backup/nosnap

   1 #!/bin/sh
   2
   3 set -e
   4
   5 removes () {
   6         if test -L "$vardir/snap-mount"; then
   7                 rm -f -- "$vardir/snap-mount"
   8         elif test -d "$vardir/snap-mount"; then
   9                 rmdir -- "$vardir/snap-mount"
  10         fi
  11         rm -f -- "$vardir/snap-device"
  12 }
  13
  14 vardir="$2"
  15
  16 case "$#.$1" in
  17 2.drop)
  18         removes
  19         ;;
  20 4.snap)
  21         removes
  22         ln -s -- "$3" "$vardir/snap-device"
  23         ln -s -- "$4" "$vardir/snap-mount"
  24         ;;
  25 *)
  26         cat >&2 <<'END'
  27 usage: .../nosnap snap VARDIR DEV MOUNT
  28        .../nosnap drop VARDIR
  29 END
  30         exit 1
  31         ;;
  32 esac