use English; use English qw( -no_match_vars ) ; # Avoids regex performance # penalty in perl 5.18 and # earlier ... if ($ERRNO =~ /denied/) { ... }
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.
This module can provoke sizeable inefficiencies for regular expressions, due to unfortunate implementation details. If performance matters in your application and you don't need $PREMATCH, $MATCH, or $POSTMATCH, try doing
use English qw( -no_match_vars ) ;
. It is especially important to do this in modules to avoid penalizing all applications which use them.