shmctl function

SysV shared memory operations 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 which will hold the returned shmid_ds structure. Returns like ioctl: the undefined value for error, ``0 but true'' for zero, or the actual return value otherwise. See also IPC::SysV documentation.