Start by reading the API documentation for Runtime.exec(), and note
that there is a return value:

 Process p = Runtime.exec(...);

Get the exit value from the Process:

 p.exitValue();

However the example you've given will most definitely *not* work as
you expect because of the pipe character. Pipes are a shell feature,
but Runtime.exec() does not use a shell to run the command. If you
want to use pipes, redirection or other shell features you must run a
shell yourself. You also need to group the arguments correctly for the
shell, e.g.:

 String[] cmd = { "/bin/sh", "-c", "ls | grep foo" };
 Process p = Runtime.exec(cmd);

/gordon