lckdo

1 moreutils moreutils

lckdo

run a program with a lock held

    			lckdo
    			options
    			lockfile
    			program
    			arguments

## DESCRIPTION

`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.

## OPTIONS

`-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.

## EXIT STATUS

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.

## AUTHOR

Michael Tokarev