sub retcode_full_test {
	# code taken from perldoc -f system
	if ($? == -1) {
		G::abend("failed to execute $?????: $!");
	}
	elsif ($? & 127) {
		G::abend(sprintf("$????? died with signal %d, %s coredump", ($? & 127),  ($? & 128) ? 'with' : 'without'));
	}
	else {
		return $? >> 8;
	}
}