Reference: semop
Author: Ellen Siever, Stephen Spainhour & Nathan Patwardhan
Date: 1999-07-02T01:37:38Z

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| Chapter 5 Function Reference |

## semop

    semop key, opstring

Calls the System V IPC system call `semop(2)` to perform semaphore operations such as signaling and waiting. opstring must be a packed array of `semop` structures. You can make each `semop` structure by saying `pack('s*', $semnum, $semop, $semflag)`. The number of semaphore operations is implied by the length of opstring. The function returns true if successful, or false if there is an error. On error, it puts the error code into `$!`. Before calling, you should say:

>     require "ipc.ph";
>     require "sem.ph";

This function is available only on machines supporting System V IPC.

Reference: semget |  | Reference: send