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\";

Answer 1

$number =~ s/^0+(?=\d)//;

The positive lookahead ensures there's at least one digit left, and using + instead of * means the substitution is skipped if there are no leading zeroes.

If you're trying to normalize groups of numbers in a single string, just use \b instead of ^, and do a global substitution:

my $data = "0225 0000 030";
$data =~ s/\b0+(?=\d)//g;