See also

• Auto-localization of $_ in while(<>)
• implicit local $_ happens sometimes
• "$_" vs. $_
• Local $$_?
• Playing with non-localized $_ in nested loops.
• Why doesn't the angle operator localize $_
• localization of $_
• Lexical $_ in given/when vs. BLOCK arguments
• Should we Localize $_ ?
• When is $_ local and when is it not?
• How do I localize $_ in while loops?