in reply to How to make all warnings FATAL via PERL5OPT

-Mwarnings=FATAL,all

$ perl -Mwarnings=FATAL,all -le " printf qq/%s %s / , 1, 2; print q/hi +/;" 1 2 hi $ perl -Mwarnings=FATAL,all -le " printf qq/%s %s / , 1; print q/hi/;" Missing argument in printf at -e line 1.