use strict;
my $str = ' 1 -1 2 SER HA H 4.477 0.003 1
2 -1 2 SER HB2 H 3.765 0.001 1
3 -1 2 SER HB3 H 3.765 0.001 1
4 -1 2 SER C C 173.726 0.2 1
5 -1 2 SER CA C 58.16 0.047 1
6 -1 2 SER CB C 64.056 0.046 1
7 0 3 HIS H H 8.357 0.004 1
8 0 3 HIS HA H 4.725 0.003 1
9 0 3 HIS HB2 H 3.203 0.003 2
.....
63 7 10 GLU HA H 4.328 0.004 1
64 7 10 GLU HB2 H 2.154 0.005 2
65 7 10 GLU HB3 H 2.156 0.004 2
66 7 10 GLU HG2 H 2.262 0.014 2
67 7 10 GLU HG3 H 2.464 0.001 2
68 7 10 GLU C C 177.242 0.2 1
69 7 10 GLU CA C 59.009 0.068 1';
my $regex = qr/\b\d+\s+[A-Z]{3}\s+[A-Z]/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