#!/usr/bin/perl -- use YAPE::Regex::Explain; die YAPE::Regex::Explain->new( qr/[{},*]/ )->explain; __END__ The regular expression: (?-imsx:[{},*]) matches as follows: NODE EXPLANATION ---------------------------------------------------------------------- (?-imsx: group, but do not capture (case-sensitive) (with ^ and $ matching normally) (with . not matching \n) (matching whitespace and # normally): ---------------------------------------------------------------------- [{},*] any character of: '{', '}', ',', '*' ---------------------------------------------------------------------- ) end of grouping ----------------------------------------------------------------------