How can I make Perl recognize paths with '~'?

Possible Duplicate:
How do I find a user's home directory in Perl?

I'm running Ubuntu.

Whenever I pass a Perl script a path that starts with ~ (e.g. ~/Documents/file.txt) it fails finding it. I must pass the canonical path (e.g. /home/dave/Documents/file.txt).

Why is that?

Can I make Perl recognize ~ paths?

UPDATE

All the suggested solutions include changing the code in the scripts. I would like for a solution that would not involve any changes to the scripts themselves (since not all of them are mine). Perhaps something in the way Bash works?

The updated version of the question was posted at Super User.

For a reliable (and easy) cross-platform method, try File::HomeDir:

use File::HomeDir;
print File::HomeDir->my_home;