IRQ: interrput request queue 中断请求队列
fg: foreground. fg用来把后台(background)程序调到前台(foreground)上来.rc: resources configuration. 资源设置,Linux中的配置文件常以此缩写结尾.FTP: File Transfer Protocol.ftpd: file transfer protocol daemon.原文：http://www.cnblogs.com/XLCYun/p/4657472.html