Command shell running in the background and foreground

Knowledge of script commands in the background
& the scripts in the background will run forever
[root @ localhost day9] # jobs [see it running in the background]
[1] + Running SH while01.sh &
[root @ localhost Day9 ] # fg 1 [to get the front desk to the implementation of this situation to the next, but the network is down, you will not executed]
sh while01.sh
suspended his press ctrl
suspend him + z press ctrl
[1] + Stopped SH while01. SH
[root @ localhost Day9] # Jobs
[1] + Stopped SH while01.sh
[root @ localhost Day9] # 1 [BG] and then run in the background
[1] + SH while01.sh &
[root @ localhost Day9] # Jobs
[. 1] + Running SH & while01.sh