pmlock (1) - Linux Manuals
pmlock: simple file-based mutex
NAME
pmlock - simple file-based mutexSYNOPSIS
$PCP_BINADM_DIR/pmlock [ -v ] fileDESCRIPTION
pmlock attempts to acquire an exclusive lock by creating file with a mode of 0.The exit status is 0 for success, 1 for failure.
To release the lock, unlink file.
In the event of a failure, the -v option produces an explanatory message on stdout.