use strict;
use warnings;
use Math::NumberBase;

my $length = 4;
my $b = Math::NumberBase->new($length);
my $start = $b->to_decimal("1" x $length);
my $end = $b->to_decimal("${\($length-1)}" x $length);

print $b->from_decimal($_), "\n" for $start .. $end;

__END__
1111
1112
1113
1120
1121
1122
1123
1130
1131
1132
1133
1200
1201
...
3310
3311
3312
3313
3320
3321
3322
3323
3330
3331
3332
3333