You are viewing the version of this documentation from Perl 5.35.1. This is a development release of Perl.
shmctl ID,CMD,ARG

Calls the System V IPC function shmctl. You'll probably have to say

use IPC::SysV;

first to get the correct constant definitions. If CMD is IPC_STAT, then ARG must be a variable that will hold the returned shmid_ds structure. Returns like ioctl: undef for error; "0 but true" for zero; and the actual return value otherwise. See also "SysV IPC" in perlipc and the documentation for IPC::SysV.

Portability issues: "shmctl" in perlport.