二、执行init程序 其次介绍init程序,利用init程序可以方便地定制启动其间装入哪些程序。init的任务是 启动新进程和退出时重新启动其它进程。例如,在大多数Linux系统中,启动时最初装入 六个虚拟的控制台进程,退出控制台窗口时,进程死亡,然后init启动新的虚拟登录控制台, 因而总是提供六个虚拟登陆控控制台进程。 控制init程序操作的规则存放在文件/etc/inittab中。Red Hat Linux缺省的inittab文 件如下: # #inittab This file describes how the INIT process should set up the system in a certain #run-level. # # #Default runlevel.The runlevels used by RHS are: #0-halt(Do NOT set initdefault to this) #1-Single user mode #2-Multiuser,without NFS(the same as 3,if you do not have networking) #3-Full multiuser mode #4-unused #5-X11 #6-reboot(Do NOT set initdefault to this) # id:3:initdefault:
#system initialization si::sysinit:/etc/rc.d/rc.sysinit 10:0:wait:/etc/rc.d/rc 0 11:1:wait:/etc/rc.d/rc 1 12:2:wait:/etc/rc.d/rc 2 13:3:wait:/etc/rc.d/rc 3 14:4:wait:/etc/rc.d/rc 4 15:5:wait:/etc/rc.d/rc 5 16:6:wait:/etc/rc.d/rc 6 #Things to run in every runlevel ud:once:/sbin/update
#Trap CTRL-ALT-DELETE ca::ctrlaltdel:/sbin/shutdown -t3 -r now
#When our UPS tells us power has failed,assume we have a few minutes of power left.Schedule a #shutdown for 2 minutes from now. #This does,of course,assume you have powered installed and your UPS connected and working #correctly. pf::powerfail:/sbin/shutdown -f -h +2 "Power Restored;Shutdown Cancelled"
#Run gettys in standard runlevels 1:12345:respawn:/sbin/minggetty tty1 2:2345:respawn:/sbin/minggetty tty2 3:2345:respawn:/sbin/minggetty tty3 4:2345:respawn:/sbin/minggetty tty4 5:2345:respawn:/sbin/minggetty tty5 6:2345:respawn:/sbin/minggetty tty6 #Run xdm in runlevel 5