+
+//usage:#define flock_trivial_usage
+//usage: "[-sxun] FD|{FILE [-c] PROG ARGS}"
+//usage:#define flock_full_usage "\n\n"
+//usage: "[Un]lock file descriptor, or lock FILE, run PROG\n"
+//usage: "\n -s Shared lock"
+//usage: "\n -x Exclusive lock (default)"
+//usage: "\n -u Unlock FD"
+//usage: "\n -n Fail rather than wait"
+