Linux开机自启动目录

1、开机启动脚本

开机启动脚本是存放在 /etc/rc.d/rcX.d 目录中的，这里的X是runlevel，就是linux的运行级别，可以看到有rc0~rc6，共7种级别：

运行级别0：系统停机状态，系统默认运行级别不能设为0，否则不能正常启动
运行级别1：单用户工作状态，root权限，用于系统维护，禁止远程登陆
运行级别2：多用户状态(没有NFS)
运行级别3：完全的多用户状态(有NFS)，登陆后进入控制台命令行模式
运行级别4：系统未使用，保留
运行级别5：X11控制台，登陆后进入图形GUI模式
运行级别6：系统正常关闭并重启，默认运行级别不能设为6，否则不能正常启动

[root@wc1 Desktop]# pwd/root/Desktop[root@wc1 Desktop]# cd /etc/rc.d[root@wc1 rc.d]# ls -ltotal 60drwxr-xr-x. 2 root root  4096 Aug 16 14:58 init.d-rwxr-xr-x. 1 root root  2617 Oct 16  2014 rcdrwxr-xr-x. 2 root root  4096 Aug 16 15:35 rc0.ddrwxr-xr-x. 2 root root  4096 Aug 16 15:35 rc1.ddrwxr-xr-x. 2 root root  4096 Aug 16 15:35 rc2.ddrwxr-xr-x. 2 root root  4096 Aug 16 15:35 rc3.ddrwxr-xr-x. 2 root root  4096 Aug 16 15:35 rc4.ddrwxr-xr-x. 2 root root  4096 Aug 16 15:35 rc5.ddrwxr-xr-x. 2 root root  4096 Aug 16 15:35 rc6.d-rwxr-xr-x. 1 root root   220 Oct 16  2014 rc.local-rwxr-xr-x. 1 root root 19914 Oct 16  2014 rc.sysinit

这里切换到rc3.d目录下，也就是完全的多用户模式：

[root@wc1 rc.d]# cd rc3.d[root@wc1 rc3.d]# ls -ltotal 0lrwxrwxrwx. 1 root root 16 Aug  4 21:08 K01smartd -> ../init.d/smartdlrwxrwxrwx. 1 root root 17 Aug  4 21:06 K02oddjobd -> ../init.d/oddjobdlrwxrwxrwx. 1 root root 17 Aug  4 21:09 K05wdaemon -> ../init.d/wdaemonlrwxrwxrwx. 1 root root 16 Aug  4 21:08 K10psacct -> ../init.d/psacctlrwxrwxrwx. 1 root root 19 Aug  4 21:06 K10saslauthd -> ../init.d/saslauthdlrwxrwxrwx. 1 root root 22 Aug  4 21:06 K15htcacheclean -> ../init.d/htcachecleanlrwxrwxrwx. 1 root root 15 Aug  4 21:06 K15httpd -> ../init.d/httpdlrwxrwxrwx. 1 root root 24 Aug  4 21:08 K30spice-vdagentd -> ../init.d/spice-vdagentdlrwxrwxrwx. 1 root root 17 Aug  4 21:06 K50dnsmasq -> ../init.d/dnsmasqlrwxrwxrwx. 1 root root 20 Aug  4 21:05 K50netconsole -> ../init.d/netconsolelrwxrwxrwx. 1 root root 15 Aug  4 21:06 K50snmpd -> ../init.d/snmpdlrwxrwxrwx. 1 root root 19 Aug  4 21:06 K50snmptrapd -> ../init.d/snmptrapdlrwxrwxrwx. 1 root root 13 Aug  4 21:05 K60nfs -> ../init.d/nfslrwxrwxrwx. 1 root root 20 Aug  4 21:05 K69rpcsvcgssd -> ../init.d/rpcsvcgssdlrwxrwxrwx. 1 root root 17 Aug  4 21:05 K73winbind -> ../init.d/winbindlrwxrwxrwx. 1 root root 14 Aug  4 13:47 K74ntpd -> ../init.d/ntpdlrwxrwxrwx. 1 root root 17 Aug  4 21:06 K75ntpdate -> ../init.d/ntpdatelrwxrwxrwx. 1 root root 19 Aug  4 21:08 K75quota_nld -> ../init.d/quota_nldlrwxrwxrwx. 1 root root 16 Aug  4 21:06 K76ypbind -> ../init.d/ypbindlrwxrwxrwx. 1 root root 15 Aug  4 13:47 K80kdump -> ../init.d/kdumplrwxrwxrwx. 1 root root 24 Aug 16 15:35 K84wpa_supplicant -> ../init.d/wpa_supplicantlrwxrwxrwx. 1 root root 21 Aug  4 21:05 K87restorecond -> ../init.d/restorecondlrwxrwxrwx. 1 root root 14 Aug 16 15:35 K88sssd -> ../init.d/sssdlrwxrwxrwx. 1 root root 15 Aug  4 21:05 K89rdisc -> ../init.d/rdisclrwxrwxrwx. 1 root root 19 Aug  4 13:47 K95firstboot -> ../init.d/firstbootlrwxrwxrwx. 1 root root 14 Aug  4 21:08 K99rngd -> ../init.d/rngdlrwxrwxrwx. 1 root root 17 Aug  4 21:07 S01sysstat -> ../init.d/sysstatlrwxrwxrwx. 1 root root 22 Aug  4 21:07 S02lvm2-monitor -> ../init.d/lvm2-monitorlrwxrwxrwx. 1 root root 22 Aug 16 14:59 S03vmware-tools -> ../init.d/vmware-toolslrwxrwxrwx. 1 root root 19 Aug  4 21:06 S08ip6tables -> ../init.d/ip6tableslrwxrwxrwx. 1 root root 18 Aug  4 21:05 S08iptables -> ../init.d/iptableslrwxrwxrwx. 1 root root 17 Aug  4 21:05 S10network -> ../init.d/networklrwxrwxrwx. 1 root root 16 Aug  4 21:08 S11auditd -> ../init.d/auditdlrwxrwxrwx. 1 root root 21 Aug  4 21:02 S11portreserve -> ../init.d/portreservelrwxrwxrwx. 1 root root 17 Aug  4 21:06 S12rsyslog -> ../init.d/rsysloglrwxrwxrwx. 1 root root 18 Aug  4 21:08 S13cpuspeed -> ../init.d/cpuspeedlrwxrwxrwx. 1 root root 20 Aug  4 21:06 S13irqbalance -> ../init.d/irqbalancelrwxrwxrwx. 1 root root 17 Aug  4 21:03 S13rpcbind -> ../init.d/rpcbindlrwxrwxrwx. 1 root root 19 Aug  4 21:05 S15mdmonitor -> ../init.d/mdmonitorlrwxrwxrwx. 1 root root 20 Aug  4 21:02 S22messagebus -> ../init.d/messagebuslrwxrwxrwx. 1 root root 24 Aug  4 21:06 S23NetworkManager -> ../init.d/NetworkManagerlrwxrwxrwx. 1 root root 17 Aug 16 15:35 S24nfslock -> ../init.d/nfslocklrwxrwxrwx. 1 root root 17 Aug 16 15:35 S24rpcgssd -> ../init.d/rpcgssdlrwxrwxrwx. 1 root root 26 Aug  4 21:07 S25blk-availability -> ../init.d/blk-availabilitylrwxrwxrwx. 1 root root 14 Aug  4 21:05 S25cups -> ../init.d/cupslrwxrwxrwx. 1 root root 15 Aug  4 21:05 S25netfs -> ../init.d/netfslrwxrwxrwx. 1 root root 15 Aug  4 21:08 S26acpid -> ../init.d/acpidlrwxrwxrwx. 1 root root 19 Aug  4 21:05 S26haldaemon -> ../init.d/haldaemonlrwxrwxrwx. 1 root root 19 Aug  4 21:05 S26udev-post -> ../init.d/udev-postlrwxrwxrwx. 1 root root 16 Aug  4 21:06 S28autofs -> ../init.d/autofslrwxrwxrwx. 1 root root 19 Aug  4 21:06 S50bluetooth -> ../init.d/bluetoothlrwxrwxrwx. 1 root root 14 Aug  4 21:07 S55sshd -> ../init.d/sshdlrwxrwxrwx. 1 root root 32 Aug 16 14:59 S57vmware-tools-thinprint -> ../init.d/vmware-tools-thinprintlrwxrwxrwx. 1 root root 15 Aug 16 15:35 S64mysql -> ../init.d/mysqllrwxrwxrwx. 1 root root 17 Aug  4 21:06 S80postfix -> ../init.d/postfixlrwxrwxrwx. 1 root root 19 Aug  4 21:03 S82abrt-ccpp -> ../init.d/abrt-ccpplrwxrwxrwx. 1 root root 15 Aug  4 21:03 S82abrtd -> ../init.d/abrtdlrwxrwxrwx. 1 root root 15 Aug  4 21:06 S90crond -> ../init.d/crondlrwxrwxrwx. 1 root root 13 Aug  4 21:03 S95atd -> ../init.d/atdlrwxrwxrwx. 1 root root 20 Aug  4 21:06 S99certmonger -> ../init.d/certmongerlrwxrwxrwx. 1 root root 11 Aug  4 21:05 S99local -> ../rc.local

发现有很多K、S开头的后面跟着2位数字的文件，比如：K15httpd，K表示关闭，而15是指关闭的 优先级，也就是linux内核会按照系统预先设置好的runlevel，比如设置为3，那么就读取/etc/rc.d/rc3.d这个目录中的文件，然后按照先执行K开头，后执行S开头，并且从数字较小的开始执行，比如这里K15httpd，也就是排在第7个开始执行。

而且可以看到 K15httpd -> ../init.d/httpd ，也就是说 K15httpd是一个连接文件，连接到了相对于当前目录的上层目录下面的init.d/httpd，也就是目录/etc/rc.d/init.d ：

[root@wc1 rc3.d]# ls -l /etc/rc.d/init.dtotal 408-rwxr-xr-x. 1 root root  1288 Oct 16  2014 abrt-ccpp-rwxr-xr-x. 1 root root  1628 Oct 16  2014 abrtd-rwxr-xr-x. 1 root root  1642 Oct 16  2014 abrt-oops-rwxr-xr-x. 1 root root  1725 Aug 19  2010 acpid-rwxr-xr-x. 1 root root  2062 Jan 30  2012 atd-rwxr-xr-x. 1 root root  3580 Oct 15  2014 auditd-rwxr-xr-x. 1 root root  4043 Oct 16  2014 autofs-r-xr-xr-x. 1 root root  1340 Oct 16  2014 blk-availability-rwxr-xr-x. 1 root root   710 Nov 11  2010 bluetooth-rwxr-xr-x. 1 root root  2094 Oct 16  2014 certmonger-rwxr-xr-x. 1 root root 11355 Aug 13  2013 cpuspeed-rwxr-xr-x. 1 root root  2826 Nov 23  2013 crond-rwxr-xr-x. 1 root root  3034 Oct 15  2014 cups-rwxr-xr-x. 1 root root  1734 Jun 16  2014 dnsmasq-rwxr-xr-x. 1 root root  3245 Jul  9  2013 firstboot-rw-r--r--. 1 root root 19295 Jul 22  2014 functions-rwxr-xr-x. 1 root root  1801 Oct 15  2014 haldaemon-rwxr-xr-x. 1 root root  5866 Jul 22  2014 halt-rwxr-xr-x. 1 root root  2001 Oct 16  2014 htcacheclean-rwxr-xr-x. 1 root root  3371 Oct 16  2014 httpd-rwxr-xr-x. 1 root root 10804 Oct 15  2014 ip6tables-rwxr-xr-x. 1 root root 10688 Oct 15  2014 iptables-rwxr-xr-x. 1 root root  1938 Jun  2  2014 irqbalance-rwxr-xr-x. 1 root root 19476 Oct 16  2014 kdump-rwxr-xr-x. 1 root root   652 Jul 22  2014 killall-r-xr-xr-x. 1 root root  2134 Oct 16  2014 lvm2-lvmetad-r-xr-xr-x. 1 root root  2757 Oct 16  2014 lvm2-monitor-rwxr-xr-x. 1 root root  2571 Sep  5  2014 mdmonitor-rwxr-xr-x. 1 root root  2200 Sep 14  2012 messagebus-rwxr-xr-x. 1 root root 10815 Jul  3  2013 mysql-rwxr-xr-x. 1 root root  2989 Jul 22  2014 netconsole-rwxr-xr-x. 1 root root  6064 Jul 22  2014 netfs-rwxr-xr-x. 1 root root  6334 Jul 22  2014 network-rwxr-xr-x. 1 root root  2205 Oct 15  2014 NetworkManager-rwxr-xr-x. 1 root root  6878 Oct 16  2014 nfs-rwxr-xr-x. 1 root root  3526 Oct 16  2014 nfslock-rwxr-xr-x. 1 root root  1923 Jul 15  2013 ntpd-rwxr-xr-x. 1 root root  2043 Jul 15  2013 ntpdate-rwxr-xr-x. 1 root root  2261 Jun 25  2011 oddjobd-rwxr-xr-x. 1 root root  2023 Apr  3  2012 portreserve-rwxr-xr-x. 1 root root  3912 Feb 20  2014 postfix-rwxr-xr-x. 1 root root  1556 Jul 17  2012 psacct-rwxr-xr-x. 1 root root  2034 Mar  5  2014 quota_nld-rwxr-xr-x. 1 root root  1513 Sep 17  2013 rdisc-rwxr-xr-x. 1 root root  1822 Oct 16  2014 restorecond-rwxr-xr-x. 1 root root  1808 Dec 18  2011 rngd-rwxr-xr-x. 1 root root  2073 Feb 22  2013 rpcbind-rwxr-xr-x. 1 root root  2518 Oct 16  2014 rpcgssd-rwxr-xr-x. 1 root root  2305 Oct 16  2014 rpcidmapd-rwxr-xr-x. 1 root root  2464 Oct 16  2014 rpcsvcgssd-rwxr-xr-x. 1 root root  2011 Aug 15  2013 rsyslog-rwxr-xr-x. 1 root root  1698 Oct 16  2014 sandbox-rwxr-xr-x. 1 root root  2056 Jun 23  2014 saslauthd-rwxr-xr-x. 1 root root   647 Jul 22  2014 single-rwxr-xr-x. 1 root root  3002 Feb 22  2013 smartd-rwxr-xr-x. 1 root root  2162 Sep 15  2014 snmpd-rwxr-xr-x. 1 root root  1738 Sep 15  2014 snmptrapd-rwxr-xr-x. 1 root root  2472 Oct 15  2014 spice-vdagentd-rwxr-xr-x. 1 root root  4621 Oct 15  2014 sshd-rwxr-xr-x. 1 root root  2690 Oct 16  2014 sssd-rwxr-xr-x. 1 root root  1144 Oct 16  2014 sysstat-rwxr-xr-x. 1 root root  2294 Oct 16  2014 udev-post-rwxr-xr-x. 1 root root 38525 Aug 16 14:58 vmware-tools-rwxr-xr-x. 1 root root 15208 Aug 16 14:58 vmware-tools-thinprint-rwxr-xr-x. 1 root root  1674 Feb 22  2013 wdaemon-rwxr-xr-x. 1 root root  1608 Oct 15  2014 winbind-rwxr-xr-x. 1 root root  1866 Feb  4  2013 wpa_supplicant-rwxr-xr-x. 1 root root  4799 Feb 22  2013 ypbind[root@wc1 rc3.d]# 

再来看一下/etc/rc.d/init.d/httpd文件的内容：

[root@wc1 rc3.d]# cat /etc/rc.d/init.d/httpd#!/bin/bash## httpd        Startup script for the Apache HTTP Server## chkconfig: - 85 15# description: The Apache HTTP Server is an efficient and extensible  \#       server implementing the current HTTP standards.# processname: httpd# config: /etc/httpd/conf/httpd.conf# config: /etc/sysconfig/httpd# pidfile: /var/run/httpd/httpd.pid#### BEGIN INIT INFO# Provides: httpd# Required-Start: $local_fs $remote_fs $network $named# Required-Stop: $local_fs $remote_fs $network# Should-Start: distcache# Short-Description: start and stop Apache HTTP Server# Description: The Apache HTTP Server is an extensible server #  implementing the current HTTP standards.### END INIT INFO# Source function library.. /etc/rc.d/init.d/functionsif [ -f /etc/sysconfig/httpd ]; then        . /etc/sysconfig/httpdfi# Start httpd in the C locale by default.HTTPD_LANG=${HTTPD_LANG-"C"}# This will prevent initlog from swallowing up a pass-phrase prompt if# mod_ssl needs a pass-phrase from the user.INITLOG_ARGS=""# Set HTTPD=/usr/sbin/httpd.worker in /etc/sysconfig/httpd to use a server# with the thread-based "worker" MPM; BE WARNED that some modules may not# work correctly with a thread-based MPM; notably PHP will refuse to start.# Path to the apachectl script, server binary, and short-form for messages.apachectl=/usr/sbin/apachectlhttpd=${HTTPD-/usr/sbin/httpd}prog=httpdpidfile=${PIDFILE-/var/run/httpd/httpd.pid}lockfile=${LOCKFILE-/var/lock/subsys/httpd}RETVAL=0STOP_TIMEOUT=${STOP_TIMEOUT-10}# The semantics of these two functions differ from the way apachectl does# things -- attempting to start while running is a failure, and shutdown# when not running is also a failure.  So we just do it the way init scripts# are expected to behave here.start() {        echo -n $"Starting $prog: "        LANG=$HTTPD_LANG daemon --pidfile=${pidfile} $httpd $OPTIONS        RETVAL=$?        echo        [ $RETVAL = 0 ] && touch ${lockfile}        return $RETVAL}# When stopping httpd, a delay (of default 10 second) is required# before SIGKILLing the httpd parent; this gives enough time for the# httpd parent to SIGKILL any errant children.stop() {echo -n $"Stopping $prog: "killproc -p ${pidfile} -d ${STOP_TIMEOUT} $httpdRETVAL=$?echo[ $RETVAL = 0 ] && rm -f ${lockfile} ${pidfile}}reload() {    echo -n $"Reloading $prog: "    if ! LANG=$HTTPD_LANG $httpd $OPTIONS -t >&/dev/null; then        RETVAL=6        echo $"not reloading due to configuration syntax error"        failure $"not reloading $httpd due to configuration syntax error"    else        # Force LSB behaviour from killproc        LSB=1 killproc -p ${pidfile} $httpd -HUP        RETVAL=$?        if [ $RETVAL -eq 7 ]; then            failure $"httpd shutdown"        fi    fi    echo}# See how we were called.case "$1" in  start)start;;  stop)stop;;  status)        status -p ${pidfile} $httpdRETVAL=$?;;  restart)stopstart;;  condrestart|try-restart)if status -p ${pidfile} $httpd >&/dev/null; thenstopstartfi;;  force-reload|reload)        reload;;  graceful|help|configtest|fullstatus)$apachectl $@RETVAL=$?;;  *)echo $"Usage: $prog {start|stop|restart|condrestart|try-restart|force-reload|reload|status|fullstatus|graceful|help|configtest}"RETVAL=2esacexit $RETVAL[root@wc1 rc3.d]# 

2、另一个开机自启动目录

这个目录就是：/etc/init.d，目录里也存放了开机自启动脚本。

不过可以发现这个目录只不过是一个连接目录，实际上对应的就是/etc/rc.d/init.d，也就是上面讲到的目录，目录中的文件和/etc/rc.d/init.d 中的文件完全一致。

[root@wc1 rc3.d]# ls -l /etc/init.dlrwxrwxrwx. 1 root root 11 Aug  4 21:02 /etc/init.d -> rc.d/init.d[root@wc1 rc3.d]# ls -l /etc/init.d/total 408-rwxr-xr-x. 1 root root  1288 Oct 16  2014 abrt-ccpp-rwxr-xr-x. 1 root root  1628 Oct 16  2014 abrtd-rwxr-xr-x. 1 root root  1642 Oct 16  2014 abrt-oops-rwxr-xr-x. 1 root root  1725 Aug 19  2010 acpid-rwxr-xr-x. 1 root root  2062 Jan 30  2012 atd-rwxr-xr-x. 1 root root  3580 Oct 15  2014 auditd-rwxr-xr-x. 1 root root  4043 Oct 16  2014 autofs-r-xr-xr-x. 1 root root  1340 Oct 16  2014 blk-availability-rwxr-xr-x. 1 root root   710 Nov 11  2010 bluetooth-rwxr-xr-x. 1 root root  2094 Oct 16  2014 certmonger-rwxr-xr-x. 1 root root 11355 Aug 13  2013 cpuspeed-rwxr-xr-x. 1 root root  2826 Nov 23  2013 crond-rwxr-xr-x. 1 root root  3034 Oct 15  2014 cups-rwxr-xr-x. 1 root root  1734 Jun 16  2014 dnsmasq-rwxr-xr-x. 1 root root  3245 Jul  9  2013 firstboot-rw-r--r--. 1 root root 19295 Jul 22  2014 functions-rwxr-xr-x. 1 root root  1801 Oct 15  2014 haldaemon-rwxr-xr-x. 1 root root  5866 Jul 22  2014 halt-rwxr-xr-x. 1 root root  2001 Oct 16  2014 htcacheclean-rwxr-xr-x. 1 root root  3371 Oct 16  2014 httpd-rwxr-xr-x. 1 root root 10804 Oct 15  2014 ip6tables-rwxr-xr-x. 1 root root 10688 Oct 15  2014 iptables-rwxr-xr-x. 1 root root  1938 Jun  2  2014 irqbalance-rwxr-xr-x. 1 root root 19476 Oct 16  2014 kdump-rwxr-xr-x. 1 root root   652 Jul 22  2014 killall-r-xr-xr-x. 1 root root  2134 Oct 16  2014 lvm2-lvmetad-r-xr-xr-x. 1 root root  2757 Oct 16  2014 lvm2-monitor-rwxr-xr-x. 1 root root  2571 Sep  5  2014 mdmonitor-rwxr-xr-x. 1 root root  2200 Sep 14  2012 messagebus-rwxr-xr-x. 1 root root 10815 Jul  3  2013 mysql-rwxr-xr-x. 1 root root  2989 Jul 22  2014 netconsole-rwxr-xr-x. 1 root root  6064 Jul 22  2014 netfs-rwxr-xr-x. 1 root root  6334 Jul 22  2014 network-rwxr-xr-x. 1 root root  2205 Oct 15  2014 NetworkManager-rwxr-xr-x. 1 root root  6878 Oct 16  2014 nfs-rwxr-xr-x. 1 root root  3526 Oct 16  2014 nfslock-rwxr-xr-x. 1 root root  1923 Jul 15  2013 ntpd-rwxr-xr-x. 1 root root  2043 Jul 15  2013 ntpdate-rwxr-xr-x. 1 root root  2261 Jun 25  2011 oddjobd-rwxr-xr-x. 1 root root  2023 Apr  3  2012 portreserve-rwxr-xr-x. 1 root root  3912 Feb 20  2014 postfix-rwxr-xr-x. 1 root root  1556 Jul 17  2012 psacct-rwxr-xr-x. 1 root root  2034 Mar  5  2014 quota_nld-rwxr-xr-x. 1 root root  1513 Sep 17  2013 rdisc-rwxr-xr-x. 1 root root  1822 Oct 16  2014 restorecond-rwxr-xr-x. 1 root root  1808 Dec 18  2011 rngd-rwxr-xr-x. 1 root root  2073 Feb 22  2013 rpcbind-rwxr-xr-x. 1 root root  2518 Oct 16  2014 rpcgssd-rwxr-xr-x. 1 root root  2305 Oct 16  2014 rpcidmapd-rwxr-xr-x. 1 root root  2464 Oct 16  2014 rpcsvcgssd-rwxr-xr-x. 1 root root  2011 Aug 15  2013 rsyslog-rwxr-xr-x. 1 root root  1698 Oct 16  2014 sandbox-rwxr-xr-x. 1 root root  2056 Jun 23  2014 saslauthd-rwxr-xr-x. 1 root root   647 Jul 22  2014 single-rwxr-xr-x. 1 root root  3002 Feb 22  2013 smartd-rwxr-xr-x. 1 root root  2162 Sep 15  2014 snmpd-rwxr-xr-x. 1 root root  1738 Sep 15  2014 snmptrapd-rwxr-xr-x. 1 root root  2472 Oct 15  2014 spice-vdagentd-rwxr-xr-x. 1 root root  4621 Oct 15  2014 sshd-rwxr-xr-x. 1 root root  2690 Oct 16  2014 sssd-rwxr-xr-x. 1 root root  1144 Oct 16  2014 sysstat-rwxr-xr-x. 1 root root  2294 Oct 16  2014 udev-post-rwxr-xr-x. 1 root root 38525 Aug 16 14:58 vmware-tools-rwxr-xr-x. 1 root root 15208 Aug 16 14:58 vmware-tools-thinprint-rwxr-xr-x. 1 root root  1674 Feb 22  2013 wdaemon-rwxr-xr-x. 1 root root  1608 Oct 15  2014 winbind-rwxr-xr-x. 1 root root  1866 Feb  4  2013 wpa_supplicant-rwxr-xr-x. 1 root root  4799 Feb 22  2013 ypbind

3、总结

/etc/rc.d/rcX.d 目录下面的文件是连接文件，连接到/etc/rc.d/init.d 目录下的文件，而/etc/init.d 目录就是链接目录，连接到 /etc/rc.d/init.d 目录。