use warnings;
use strict;

while (<DATA>) {
    chomp;
    my @numbers = unpack ("(a2)*", $_);

    print "unpacked: @numbers, ";

    @numbers = /(..)/g;
    print "matched: @numbers, ";

    @numbers = ();
    push @numbers, substr $_, 0, 2, '' while length $_;
    print "substr'd: @numbers\n";
}

__DATA__
0912203749
0725284648
0608294149
0622424347
1219303436
1729313449
1015162331

##</code><code>##

unpacked: 09 12 20 37 49, matched: 09 12 20 37 49, substr'd: 09 12 20 37 49
unpacked: 07 25 28 46 48, matched: 07 25 28 46 48, substr'd: 07 25 28 46 48
unpacked: 06 08 29 41 49, matched: 06 08 29 41 49, substr'd: 06 08 29 41 49
unpacked: 06 22 42 43 47, matched: 06 22 42 43 47, substr'd: 06 22 42 43 47
unpacked: 12 19 30 34 36, matched: 12 19 30 34 36, substr'd: 12 19 30 34 36
unpacked: 17 29 31 34 49, matched: 17 29 31 34 49, substr'd: 17 29 31 34 49
unpacked: 10 15 16 23 31, matched: 10 15 16 23 31, substr'd: 10 15 16 23 31