use strict;
my $str = '1) First question with 4 choices ?
a) First choice b) Second choice c) Third choice d) Last choice
2) Second question with only 3 choices ?
a) First choice b) Second choice c) Last choice
3) True or False ?
a) True b) False';
my $regex = qr/(?P<q_num>\d{1,3})\)\s?(?P<quest>.+)\n
(\s?a\)\s?)(?P<ans_a>(?:(?![a-d]\)).)+)
(b\)\s?)(?P<ans_b>(?:(?![a-d]\)).)+)
((c\)\s?)(?P<ans_c>(?:(?![a-d]\)).)+))?
((d\)\s?)(?P<ans_d>(?:(?![a-d]\)).)+))?/xp;
if ( $str =~ /$regex/g ) {
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