...进程创建(process creation) 终端字符进程(teminal character processes(MUX- and LAN-based) 用sar -w命令分析进程的deactivation/reactivation and switching activities of the system; ..
Similarly, the backgroundtaskexpectsinputfrom the controllingterminal, but the controlling terminal has no way of directing anycharactersyoutypeto the stdinof a background process.