bg

Move foreground jobs to the background.

Synopsis

bg [job_spec ...]

Main Purpose

• Used to place jobs in the background, allowing other tasks to be executed in the foreground. The effect of running this command is the same as adding the symbol & after a command, both of which execute it in the system background.

• If there is only one job in the background, the job ID can be omitted when using this command.

Parameters

job_spec (optional): Specifies the identifier of the job(s) to be moved to the background for execution. Multiple identifiers can be specified.

Return Value

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

Examples

# Run the sleep command, then press Ctrl+z.
sleep 60
^Z
[1]+  Stopped                 sleep 60

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

# Return information:
[1]+ sleep 60 &

Notes

1. Bash's job control commands include bg, fg, kill, wait, disown, and suspend.
2. This command requires the monitor option of set to be enabled; check the job control status by typing set -o and looking for the monitor line; execute set -o monitor or set -m to enable this option.
3. This command is a bash built-in; for related help information, please use the help command.