Need a basename function in Javascript

Question

I need a short basename function (one-liner ?) for Javascript:

basename("/a/folder/file.a.ext") -> "file.a"
basename("/a/folder/file.ext") -> "file"
basename("/a/folder/file") -> "file"

That should strip the path and any extension.

Update: For dot at the beginning would be nice to treat as "special" files

basename("/a/folder/.file.a.ext") -> ".file.a"
basename("/a/folder/.file.ext") -> ".file"
basename("/a/folder/.file") -> ".file" # empty is Ok
basename("/a/folder/.fil") -> ".fil"  # empty is Ok
basename("/a/folder/.file..a..") -> # does'nt matter

Answer 1

function baseName(str)
{
   var base = new String(str).substring(str.lastIndexOf('/') + 1); 
    if(base.lastIndexOf(".") != -1)       
       base = base.substring(0, base.lastIndexOf("."));
   return base;
}

If you can have / and \ as separators, you have to change the code to add one more line

Answer 2

function basename(url){
    return ((url=/(([^\/\\\.#\? ]+)(\.\w+)*)([?#].+)?$/.exec(url))!= null)? url[2]: '';
}

Answer 3

Fairly simple using regex:

function basename(input) {
   return input.split(/\.[^.]+$/)[0];
}

Explanation:

Matches a single dot character, followed by any character except a dot ([^.]), one or more times (+), tied to the end of the string ($).

It then splits the string based on this matching criteria, and returns the first result (ie everything before the match).

[EDIT] D'oh. Misread the question -- he wants to strip off the path as well. Oh well, this answers half the question anyway.

Answer 4

 basename = function(path) {
    return path.replace(/.*\/|\.[^.]*$/g, '');
 }

replace anything that ends with a slash .*\/ or dot - some non-dots - end \.[^.]*$ with nothing