
Here's a small UNIX tip (or how-to) for executing a command in the background. For UNIX gurus, this tip might seem like a basic one. But for guys like me who are coming from a Windows background, even smaller ones makes a big difference.

This is the scenario - I use Putty to login to UNIX. I execute few (internal) UNIX commands which are time thirtsy and take at least 2 hours to complete. While the command is running, I can't do anything in the Putty terminal. All I can do is stare the Putty for 2 hours or do the below, to reuse the Putty session for other tasks while running the time-thirsty command in the background.

- In UNIX shell, type your command and hit Enter.
  $ my-long-running-command
  ...... the long-running command running .....

- Your command will start running. Now press `Ctrl z`. This will interrupt the current process and pauses it. You'll see something like this;
  [1] Stopped my-long-running-command

- Now , type `bg` and hit Enter. Your current process (i.e. the command) will start running in the background. To check, type `jobs` in the command line and hit Enter. You'll see the job status something like this.
  $ bg
  [1] my-long-running-command
  $jobs
  [1]- Running my-long-running-command

So, now you can use Putty for other tasks, while your command executes in the background.


#unix (1)