$ perl -we 'open O, "> /dev/null"; print O (scalar readline)' Filehandle O opened only for output at -e line 1. 11 [main] perl 4756 _cygtls::handle_exceptions: Error while dumping state ( probably corrupted stack) Segmentation fault (core dumped) $ perl -e 'warn readline()' Warning: something's wrong at -e line 1.