+# Takes a lockfile path and command to execute once the lock is acquired.
+#
+# Retries every second for 5 minutes.
+#
+# with_lock "foo.lock" "echo a" # Works
+# with_lock "foo.lock" "echo b1 ; echo b2" # Work
+# function several() {
+# echo several1 ; echo several2
+# }
+# with_lock "foo.lock" several # Works
+#
+function with_lock() {
+ lockfile="$1"
+ block="$2"
+ with_lock_has_lock=1
+
+ trap with_lock_unlock_if_held INT TERM EXIT
+ lockfile -1 -r 300 "$lockfile"
+ with_lock_has_lock=$?
+ if [ $with_lock_has_lock -ne 0 ] ; then
+ exit $?
+ fi
+ eval "$block"
+ rm -f "$lockfile"
+ with_lock_has_lock=1
+}
+
+function with_lock_unlock_if_held() {
+ if [[ "$with_lock_has_lock" -eq 0 ]] ; then
+ rm -f "$lockfile"
+ fi
+}
+
+