$ perl -w -e 'my $a, $x, $y, $z = foo()'
Parentheses missing around "my" list at -e line 1.
Useless use of a variable in void context at -e line 1.
Useless use of a variable in void context at -e line 1.
Name "main::x" used only once: possible typo at -e line 1.
Name "main::z" used only once: possible typo at -e line 1.
Name "main::y" used only once: possible typo at -e line 1.
Undefined subroutine &main::foo called at -e line 1.