The question was more directed to the behaviour of the apparent concatenation and in the simplest case how best to treat a string that is formatted as such.

As I explained above, if the leading-zeros value is read from a file, the keyboard, a DB, or any other source, you do not have to do anything, Perl will treat them exactly as you want them to be treated.

The only time this arises is if you type leading zeros on values in your source code. So don't do that.

That's not to say that don't I wish it were not the case that leading-zero numbers were taken to be octal; or that I don't wish that it could be changed. But it can't and won't, so there's no point wishing for it. :(

But in the big picture, omitting leading zeros in source code is not so hard.