use strict;
use warnings;

my $str = "ab12c\nde34f\ngh56i\njk78l";

my @digits = $str =~ /(\d+)/g;
print "\@digits -- @digits\n\n";

my ($span_d) = $str =~ /(\d\d.*?\d\d)/;
print "\$span_d -- $span_d\n\n";

my ($span_m) = $str =~ /(\d\d.*?\d\d)/m;
print "\$span_m -- $span_m\n\n";

my ($span_s) = $str =~ /(\d\d.*?\d\d)/s;
print "\$span_s -- $span_s\n\n";