Ctrl+Z - 暂停进程并放入后台
jobs - 显示当前暂停的进程
bg N 使第N个任务在后台运行
fg N 使第N个任务在前台运行
bg, fg 不带 N 时表示对最后一个进程操作
On Unix-like systems, Control+Z is the most common default keyboard mapping for the key sequence that suspends a process.[2] When entered by a user at their computer terminal, the currently running foreground process is sent a "terminal stop" (SIGTSTP) signal, which generally causes the process to suspend its execution. The user can later continue the process execution by using the "foreground" command (fg) or the "background" command (bg).
