Calls the System V IPC function msgctl(2). 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 msqid_ds
structure. Returns like ioctl:
the undefined value for error, "0 but true"
for zero, or the actual
return value otherwise. See also SysV IPC in perlipc and the
documentation for IPC::SysV and
IPC::Semaphore .
Portability issues: msgctl in perlport.