use strict;
my $str = 'BBA -> true
ABB -> true
BAB -> true
CCA -> true
AAA -> false (change "[B-Z]" to "[A-Z]" to match this)
CCB -> false
ABC -> false
BAC -> false
BBBA -> false (there have to be only two)
ABBB -> false (there have to be only two)
ABBA -> false (there has to be only one A)
BABA -> false (there has to be only one A)
BBAA -> false (there has to be only one A)';
my $regex = qr/\b(?=[A-Z]{3}\b)A?([B-Z])A?\1A?\b/mp;
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