Actually, a dot star can be quite useful, and is considerably faster than using the non-greedy version. In this example, using dot star makes it easy, e.g.,

/^.*\\(.*)/
[download]

That will extract all the information after the last \. Using the .*? version it would have to be:

/.*?\\(?!.*\\)$/
[download]

This would aslo make it a lot slower.

However, trying to find the last \, like in this example, could probably be made simpler by a call to reverse. Though, in the example of extracting a filename, definately you should use a module like File::Basename, as aforementioned. This way it will be portable accross systems, and it is tested for errors, so it will save you valuable time trying to fix a regex that has something wrong with it(and errors always slip in, as do special cases).