1.3.5 Parallel Commands Your shell will also allow the user to launch parallel commands. This is accomplished with the ampersand operator as follows: TEDShell> cmd1 & cmd2 args1 args2 & cmd3 args1 In this case, instead of running cmd1 and then waiting for it to finish, your shell should run cmd1, cmd2, and cmd3 (each with whatever arguments the user has passed to it) in parallel, before waiting for any of them to complete. Then, after starting all such processes, you must make sure to use wait () (or waitpid) to wait for them to complete. After all processes are done, 5 return control to the user as usual (or, if in batch mode, move on to the next line)