use strict;
my $str = 'SG1
SG4
AL2
AL6
AL7
AL10
WD4
WD7
WD23
WD25
HP1
HP3
HP4
LU1';
my $regex = qr/^([sS][gG][1|4]|[aA][lL][6-7|10|2-3]|[wW][dD][23|25|7|4]|[hH][pP][1|3-4]|[lL][uU]1)\d?\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