Send a job to background
Syntax bg [job_id...]
Send the specified jobs to the background. A background job is executed simultaneously with fish, and does not have access to the keyboard. If no job is specified, the last job to be used is put in the background.
bg takes a “job ID” available from jobs, not a PID.
If jobspec is not present, the shell's notion of the current job is used.
Put the job with job id 0 in the background:
$ bg %0
To start a new process in the background you can do:
$ long_running_command &
"I'm not kidding myself, my voice is ordinary. If I stand still while I'm singing, I might as well go back to driving a truck" ~ Elvis Presley
Related bash commands:
fg - Send job to foreground
jobs - List active jobs
suspend - Suspend execution of this shell
wait - Wait for a process to complete