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       lckdo - run a program with a lock held


       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

                                  2007-08-15                          lckdo(1)