摘要：
/etc/rc.d/rc0.d/etc/rc.d/rc1.d/etc/rc.d/rc3.d/etc/rc.d/rc5.d分别对应着0,1,3,5这几个运行级别，关于运行级别的官方解释如下（以红帽为例）：# 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 - Ful 阅读全文
