=over =item getpgrp PID X X Returns the current process group for the specified PID. Use a PID of C<0> to get the current process group for the current process. Will raise an exception if used on a machine that doesn't implement getpgrp(2). If PID is omitted, returns process group of current process. Note that the POSIX version of C does not accept a PID argument, so only C is truly portable. =back