lckdo − run a program with a lock held
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lckdo [options] {lockfile} {program} [arguments] |
lckdo runs a program with a lock held, in order to prevent multiple processes from running in parallel. Use just like nice or nohup.
Now that util−linux contains a similar command named flock, lckdo is deprecated, and will be removed from some future version of moreutils.
−w
If the lock is already held by another process, wait for it to complete instead of failing immediately.
−W {sec}
The same as −w but wait not more than sec seconds.
−e
Execute the program directly without forking and waiting (keeps an extra file descriptor open).
−E {nnn}
Set the file descriptor number to keep open when exec()ing (implies −e).
−n
Do not create the lock file if it does not exist.
−q
Produce no output if lock is already held.
−s
Lock in shared (read) mode.
−x
Lock in exclusive (write) mode (default).
−t
Test for lock existence.
If the lock was successfully acquired, the return value is that of the program invoked by lckdo. If the lock couldn't be acquired, EX_TEMPFAIL is returned. If there was a problem opening/creating or locking the lock file, EX_CANTCREAT or EX_OSERR will be returned.
Michael Tokarev