perl -MO=Deparse -p -n -e 1 LINE: while (defined($_ = )) { '???'; } continue { die "-p destination: $!\n" unless print $_; } -e syntax OK perl -MO=Deparse -n -p -e 1 LINE: while (defined($_ = )) { '???'; } continue { die "-p destination: $!\n" unless print $_; } -e syntax OK'