Regular expression to remove a file's extension

Question

I am in need of a regular expression that can remove the extension of a filename, returning only the name of the file.

Here are some examples of inputs and outputs:<

Answer 1

Just for completeness: How could this be achieved without Regular Expressions?

var input = 'myfile.png';
var output = input.substr(0, input.lastIndexOf('.')) || input;

The || input takes care of the case, where lastIndexOf() provides a -1. You see, it's still a one-liner.