getpgrp
PID
This function returns the current process group for the specified
PID
(use a
PID
of 0 for the current process).
Invoking
getpgrp
will produce a fatal error if used on a machine
that doesn't implement
getpgrp
(2). If
PID
is omitted, the
function returns the process group of the current process (the same as
using a
PID
of 0). On systems implementing this operator with the
POSIX
getpgrp
(2) system call,
PID
must be omitted or, if
supplied, must be 0.