% cd /usr/local/lib/perl5
% find . -type f -exec grep -l 'warnings::warn' {} \;
./5.8.0/alpha-dec_osf/DB_File.pm
./5.8.0/alpha-dec_osf/Socket.pm
./5.8.0/alpha-dec_osf/IO/Select.pm
./5.8.0/charnames.pm
./5.8.0/constant.pm
./5.8.0/open.pm
./5.8.0/overload.pm
./5.8.0/syslog.pl
./5.8.0/vars.pm
./5.8.0/warnings.pm
./5.8.0/Tie/Handle.pm
./5.8.0/Tie/Hash.pm
./5.8.0/Tie/Scalar.pm
./5.8.0/I18N/Collate.pm
./5.8.0/File/Find.pm
./5.8.0/Class/Struct.pm
./5.8.0/pod/perllexwarn.pod
./5.8.0/pod/perltoc.pod