use strict;
my $str = '';
my $regex = qr/^( *)( *)( *)(['.-])((?!\4)(?4)+?)((?!\4|\5)(?4)++)\1\3whale
(?=.(.))\6.\7\4(?!\4|\6)([_\/])\3(?!(?11))\8\2(?=\2)\3\1_((?=\4+.).\5(?!\6)\5)(?!.?')\7\4
(?=.\7)\6.([,`])\3{2}(?=.((?!\8)[_\/])\11)\Q(_\E.\4{2}(?!\.)\5((?!\10)(?10)(?!\4+|\5|\6))\1\3{3}(\\)
(\3{3})\13\2{2}\1{1}\3+(?<=\S {10})\4\1\3\|
\1(?=\12)(?12)(?!`,)\10\4(\11{2})\4\14\10\15\9\8
\14{2}(?=\6)['-]\4(?<!-)\11\8\11\4\6\11\15\.-|(?!)/p;
if ( $str =~ /$regex/ ) {
print "Whole match is ${^MATCH} and its start/end positions can be obtained via \$-[0] and \$+[0]\n";
# print "Capture Group 1 is $1 and its start/end positions can be obtained via \$-[1] and \$+[1]\n";
# print "Capture Group 2 is $2 ... and so on\n";
}
# ${^POSTMATCH} and ${^PREMATCH} are also available with the use of '/p'
# Named capture groups can be called via $+{name}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html