- Running Programs in Background, and Output Redirection.
  (Unix/Linux)

  When you type

    $ run myprog

  the program 'myprog' executes in 'foreground'
  i.e. you have to wait for your program to finish
  before you can issue other commands (you have to wait
  for your $ prompt to appear).

  An alternative way to execute a program is to run it
  in 'background'. This is achieved with the & symbol:

    $ run myprog &

  This puts the program execution into background leaving
  you free to issue other commands, or even logoff, while you
  wait for your program to finish. This is useful for programs
  that take a few minutes or more to run (but not useful if your
  program requires keyboard input).

  When running a program in background it is sometimes necessary
  to redirect its screen output to a file, this is done using the
  '>' (output redirection) symbol:

    $ run myprog > myprog.output &

  This command sequence reads "run the program called myprog
  redirecting the screen output to the file called myprog.output;
  do all of this in background".

  You can also use output redirection for programs running in
  foreground (simply omit the & symbol from the last example).

  The command 'submit' does all this for you, e.g. 

    $ submit myprog

  the 'submit' command sends you an email when your program has
  finished.