Asynchronous shell commands

Question

I\'m trying to use a shell script to start a command. I don\'t care if/when/how/why it finishes. I want the process to start and run, but I want to be able to get back to my

Answer 1

Everyone just forgot disown. So here is a summary:

• & puts the job in the background.

  • Makes it block on attempting to read input, and
  • Makes the shell not wait for its completion.

• disown removes the process from the shell's job control, but it still leaves it connected to the terminal.

  • One of the results is that the shell won't send it a SIGHUP(If the shell receives a SIGHUP, it also sends a SIGHUP to the process, which normally causes the process to terminate).
  • And obviously, it can only be applied to background jobs(because you cannot enter it when a foreground job is running).

• nohup disconnects the process from the terminal, redirects its output to nohup.out and shields it from SIGHUP.

  • The process won't receive any sent SIGHUP.
  • Its completely independent from job control and could in principle be used also for foreground jobs(although that's not very useful).
  • Usually used with &(as a background job).