source: trunk/essentials/dev-lang/perl/pod/perlreref.pod

=head1 NAME

perlreref - Perl Regular Expressions Reference

=head1 DESCRIPTION

This is a quick reference to Perl's regular expressions.
For full information see L<perlre> and L<perlop>, as well
as the L</"SEE ALSO"> section in this document.

=head2 OPERATORS

  =~ determines to which variable the regex is applied.
     In its absence, $_ is used.

        $var =~ /foo/;

  !~ determines to which variable the regex is applied,
     and negates the result of the match; it returns
     false if the match succeeds, and true if it fails.

       $var !~ /foo/;

  m/pattern/igmsoxc searches a string for a pattern match,
     applying the given options.

        i  case-Insensitive
        g  Global - all occurrences
        m  Multiline mode - ^ and $ match internal lines
        s  match as a Single line - . matches \n
        o  compile pattern Once
        x  eXtended legibility - free whitespace and comments
        c  don't reset pos on failed matches when using /g

     If 'pattern' is an empty string, the last I<successfully> matched
     regex is used. Delimiters other than '/' may be used for both this
     operator and the following ones.

  qr/pattern/imsox lets you store a regex in a variable,
     or pass one around. Modifiers as for m// and are stored
     within the regex.

  s/pattern/replacement/igmsoxe substitutes matches of