use strict;
my $str = 'RC
RC[1]
RC[-1]
R[1]C
R[-1]C
R[1]C[1]
R[-1]C[1]
R[1]C[-1]
R[-1]C[-1]
R[0]C[1]
RC[0]
R[1]C[0]';
my $regex = qr/R(\[-?[1-9][0-9]*\])C(\[-?[1-9][0-9]*\])|R(\[-?[1-9][0-9]*\])C|RC(\[-?[1-9][0-9]*\])/p;
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