nosnap

[chiark-utils.git] / backup / nosnap

diff --git a/backup/nosnap b/backup/nosnap
new file mode 100755 (executable)
index 0000000..c1f16dd
--- /dev/null
+++ b/backup/nosnap
@@ -0,0 +1,27 @@
+#!/bin/sh
+
+set -e
+
+removes () {
+       rm -f -- "$vardir/snap-mount" "$vardir/snap-device"
+}
+
+vardir="$2"
+
+case "$#.$1" in
+2.drop)
+       removes
+       ;;
+4.snap)
+       removes
+       ln -s -- "$3" "$vardir/snap-device"
+       ln -s -- "$4" "$vardir/snap-mount"
+       ;;
+*)
+       cat >&2 <<'END'
+usage: .../nosnap snap VARDIR DEV MOUNT
+       .../nosnap drop VARDIR
+END
+       exit 1
+       ;;
+esac