folder copy with mutex

folder-copy.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+
+lockfile=lock
+
+: >> ${lockfile}
+
+exec 9>${lockfile}
+if ! flock -n 9  ; then
+    #Another instance is running
+    exit 1
+fi
+
+#TODO: rsync
+
+: > ${lockfile}