English - use nice English (or awk) names for ugly punctuation variables
use English;
...
if ($ERRNO =~ /denied/) { ... }
This module provides aliases for the built-in variables whose names no one seems to like to read. Variables with side-effects which get triggered just by accessing them (like 0ドル) will still be affected.
For those variables that have an awk version, both long and short English alternatives are provided. For example, the $/
variable can be referred to either $RS or $INPUT_RECORD_SEPARATOR if you are using the English module.
See perlvar for a complete list of these.