$ perl -le "sub f($$@@){warn qq{@_}}; f(@ARGV,@ARGV,@ARGV); " 1 2 3 4 5 Malformed prototype for main::f: 29673@@ at -e line 1. $ perl -le " eval q{sub f($$@@){warn qq{@_}}}; f(@ARGV,@ARGV,@ARGV); " 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 at (eval 1) line 1. $ perl -le " sub f($$@@); eval q{sub f($$@@){warn qq{@_}}}; f(@ARGV,@ARGV,@ARGV); " 1 2 3 4 5 Malformed prototype for main::f: 29673@@ at -e line 1.