regex - Remove leading zeroes but not all zeroes

Question

How can I remove all the leading zeroes but leave a final zero if the value only contains zeroes?

for example:

my $number = "0000";

I would like to have:

my $number = "0";

I tried:

$number =~ s/^0*//; 

but this of course removes all the zeroes in this case.

Answer 1

This should work:

$number =~ s/^0*(d+)$/$1/;

0    -> 0
0000 -> 0
0001 -> 1

Edit: turns out that's just a bit too complicated. This should also work:

$number =~ s/0*(d+)/$1/;

but I'm not sure which is better, depends on the use case.

Do check out the answer from Oesor: it's pretty sweet too, no regex involved.