--------------------------------------------------------------
#!/usr/bin/perl

@list = ("1", "3.4b.4", "2", "15", "123", "2.2", "2.13", "2.1.7", "3112", "3.4a", "1.5.32.1", "3.4.1", "3.1.5", "3.4b.1");

foreach $section (@list) {
        my @subSections = split (/\./, $section);
        for (my $x=0; $x <= $#subSections; $x++) {
                if ($maxdigit[$x] <  length($subSections[$x])) { $maxdigit[$x] = length($subSections[$x]); }
        }
}

my @paddedList = ();
foreach $section (@list) {
        my @subSections = split (/\./, $section);
        my $paddedSection = "";
        for (my $x=0; $x <= $#subSections; $x++) {
                my $padding = "";

                for(my $y = 0; $y < $maxdigit[$x]-length($subSections[$x]); $y++) { $padding .= "0"; }
                $paddedSection .= "$padding$subSections[$x].";
        }
        $paddedSection =~ s/\.$//;
        push (@paddedList, $paddedSection);
}

@sortedList = sort @paddedList;

foreach $section (@sortedList) {
        my @subSections = split (/\./, $section);

        my $unPaddedSection = "";
        for (my $x=0; $x <= $#subSections; $x++) {
                $subSections[$x] =~ s/^0*//;
                $unPaddedSection .= "$subSections[$x].";
        }
        $unPaddedSection =~ s/\.$//;
        push (@unPaddedList, $unPaddedSection);
}

foreach $li (@unPaddedList) {
        print "$li\n";
}
--------------------------------------------------------------