semop - SysV semaphore operations

- NAME
- SYNOPSIS
- DESCRIPTION

# NAME

semop - SysV semaphore operations

# SYNOPSIS

semop KEY,OPSTRING

# DESCRIPTION

Calls the System V IPC function semop to perform semaphore operations such as signalling and waiting. OPSTRING must be a packed array of semop structures. Each semop structure can be generated with `pack("s!3", $semnum, $semop, $semflag)`. The length of OPSTRING implies the number of semaphore operations. Returns true if successful, or false if there is an error. As an example, the following code waits on semaphore $semnum of semaphore id $semid:

        $semop = pack("s!3", $semnum, -1, 0);
        die "Semaphore trouble: $!\n" unless semop($semid, $semop);

To signal the semaphore, replace `-1` with `1`. See also SysV IPC in the perlipc manpage, `IPC::SysV`, and `IPC::SysV::Semaphore` documentation.

semop - SysV semaphore operations