$ perle ' my $base = "1231600014"; my @possibles = qw{ 012212316000140 01221231600014 2212316000140 1221231600014 221231600014 1231600014 }; my $re = qr{${base}\d?$}; for (@possibles) { if (/$re/) { say "$_ MATCH"; } else { say "$_ NO MATCH"; } } ' 012212316000140 MATCH 01221231600014 MATCH 2212316000140 MATCH 1221231600014 MATCH 221231600014 MATCH 1231600014 MATCH