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If I start a process by typing it in normally at the command line, such as 

wget http://site.com/bigfile.zip

and then decide I want to move that to the background, I know that I can use something like ctrl+z and then bg 1 (or jobs first if needed to get the id) to put it in the background.

My question is if there is a way to move a job from the foreground directly to the background without stopping it - like another shortcut besides ctrl+z that would do that.

I also realize that I can append & to the end of the original command to start it in the background, but the question is in regards to when you start a process in the foreground and then realize you want to move it to the background.

cwd
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2 Answers2

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Yes, absolutely: screen(1) is the answer.

To get started, add screen -R to ~/.bash_profile or equivalent, log out, and log back in.

To continue what's running in the background, press Control-A then N. This will create a new terminal screen in the foreground while seamlessly continuing your running process on the background.

Press Control-A then " to get an interactive list of screens that you have open, or press Control-A then a number to switch directly to a specific screen.

Your original requirement was to be able to move a process to the background without stopping it. Screen has two additional benefits, and these are huge if you like to do multiple things at once:

  1. You can switch between processes much more fluidly than by using Control-Z, bg, fg, etc.
  2. If your terminal session gets disconnected, your processes (like wget http://example.com/bigfile.iso) will NOT terminate! All of your shell sessions will be there waiting for you when you reconnect.

For more information, read the screen(1) manpage, or the GNU Screen Manual.

Skyhawk
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bg starts a job that was stopped, and leaves it running in the background. Basically fg and bg do the same, they resume a process, but fg does it in the foreground while bg does it in the background.

Just run bg %(number of the job) and you will have an output saying "runnning". If you check your jobs, you will see that your job is running and not stopped.

Stuggi
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Vcoe
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