Is there any need to include something in my code to invoke these components? - xpcom

Question

var localFile = Components.classes["#mozilla.org/filelocal;1"].createInstance(Components.interfaces.nsILocalFile);
localFile.initWithPath("C:\Windows\system32\cmd.exe");
var process = Components.classes["#mozilla.org/processutil;1"].createInstance(Components.interfaces.nsIProcess);
process.init(localFile);
var args=null;
process.run(false, args, args.length);
I am using Firefox/3.6. The above code is not getting invoked. I wanna that is there any need to include something in my code to invoke these components. In my browser these XPComponent are available as i checked using **
XPComViewer.
Plzzz Reply ASAP.
Regards, rAHUL......
i did like this only but i am getting the following error:
Error: Permission denied for http://localhost:8080 to get property XPCComponents.classes Source File: localhost:8080/ViewerSoln Line: 60
i am trying this on Firefox 2.0 and 3.6 both. its windows environment. please suggest me something ASAP.
Thank you,
Rahul.

Answer 1

Set up the development environment and check the Error Console. That would give you hints as to what your problem is.
Just copy the snippet from https://developer.mozilla.org/en/Code_snippets/Running_applications#Using_nsIProcess, that will give you correct code to get the necessary services.
Two less obvious errors are that a '\' has a special meaning and needs to be escaped (as in the linked snippet) and args=null won't work because you try to get its length a line later. You want args=[].
Finally, you didn't say where you're trying to run this from.