bg

Move foreground terminal jobs to run in the background

Summary

bg [job_spec ...]

The main purpose

• Used to run jobs in the background so that other tasks can be performed in the foreground. The running effect of this command is the same as adding the symbol & after the command, both of which are executed in the background of the system.

• If there is only one background task, the task number can be omitted when using this command.

Parameters

job_spec (optional): Specifies the job identifier to be moved to the background for execution, which can be one or more.

return value

Returns successful unless job control is not enabled or an error occurs.

example

#Run the sleep command and press ctrl+z.
sleep 60
^Z
[1]+ Stopped sleep 60

# Use the bg command to run the job in the background.
bg %1

# returned messages:
[1]+sleep 60&

Notice

• The job control commands of bash include bg fg kill wait disown suspend.

• This command can only be executed when the set option monitor is turned on; to view the job control status: enter set -o to view the monitor line; execute set -o monitor or set -m to turn it on this option.

• This command is a built-in bash command. For related help information, please see the help command.