Line breaks in Perl are ignored (unless they're in the middle of a quoted string, identifier, etc.), so you shouldn't have any problems splitting it up onto multiple lines.
A script I downloaded was formatted the same way. I suspect the author did it intentionally to discourage people from making changes to it.
I thought I saw a utility for automatically reformatting a Perl script, but can't remember where.
[edit]
Hmmmm ...
When you say it's one line, are there embedded line feed characters visible? That could happen if you try to view a Unix-formatted text file in Notepad on windows. If that's the case, try using Wordpad or another text editor which handles the different line terminators correctly.
