New Post: How to deal with the error stream when using ShellStream

On second glance i found a bug in your code:

                if (shells.CanRead)
                    output = shells.ReadLine();
                match = regex.Match(output);

match.Success will never become true. ReadLine() blocks till a newline appears.
But the shell-prompt "user@host:~$" doesn't have one
=> endless blocking of Readline() and your loop would never exit.