Perl::Critic::Policy::RegularExpressions::RequireLineBoundaryMatching(3pm) User Contributed Perl Documentation Perl::Critic::Policy::RegularExpressions::RequireLineBoundaryMatching(3pm)

Perl::Critic::Policy::RegularExpressions::RequireLineBoundaryMatching - Always use the "/m" modifier with regular expressions.

This Policy is part of the core Perl::Critic distribution.

Folks coming from a "sed" or "awk" background tend to assume that '$' and '^' match the beginning and end of the line, rather than then beginning and end of the string. Adding the '/m' flag to your regex makes it behave as most people expect it should.

my $match = m{ ^ $pattern $ }x;  #not ok
my $match = m{ ^ $pattern $ }xm; #ok

This Policy is not configurable except for the standard options.

For common regular expressions like e-mail addresses, phone numbers, dates, etc., have a look at the Regexp::Common module. Also, be cautions about slapping modifier flags onto existing regular expressions, as they can drastically alter their meaning. See http://www.perlmonks.org/?node_id=484238 for an interesting discussion on the effects of blindly modifying regular expression flags.

Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>

Copyright (c) 2005-2011 Imaginative Software Systems. All rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The full text of this license can be found in the LICENSE file included with this module.

2023-07-26 perl v5.38.0