ubuntu系统中/etc/rc.local和/etc/init.d/rc.local的区别详解

前言

我们在ubuntu下要把一个程序加入开机启动，一般可以通过修改rc.local来完成，但ubuntu下有两个rc.local文件。分别是/etc/rc.local和/etc/init.d/rc.local。可以看一下两个文件的内容找到他俩的关系：

/etc/init.d/rc.local

				?

									#! /bin/sh

									### BEGIN INIT INFO

									# Provides:  rc.local

									# Required-Start: $all

									# Required-Stop:

									# Default-Start: 2 3 4 5

									# Default-Stop:

									# Short-Description: Run /etc/rc.local if it exist

									### END INIT INFO

									PATH=/sbin:/usr/sbin:/bin:/usr/bin

									. /lib/init/vars.sh

									. /lib/lsb/init-functions

									do_start() {

									 if [ -x /etc/rc.local ]; then

									  [ "$VERBOSE" != no ] && log_begin_msg "Running local boot scripts (/etc/rc.local)"

									 /etc/rc.local

									 ES=$?

									 [ "$VERBOSE" != no ] && log_end_msg $ES

									 return $ES

									 fi

									}

									case "$1" in

									 start)

									 do_start

									 ;;

									 restart|reload|force-reload)

									 echo "Error: argument '$1' not supported" >&2

									 exit 3

									 ;;

									 stop)

									 ;;

									 *)

									 echo "Usage: $0 start|stop" >&2

									 exit 3

									 ;;

									esac

从注释可以看出该脚本运行在2 3 4 5的启动级别，只能处理start的参数，然后执行start，如果有/etc/rc.local文件的话则执行/etc/rc.local。如果要把开机启动的程序放/etc/init.d/rc.local文件里，记住千万别一股脑写文件最后面就行了，因为在case语句块里脚本就会退出。

/etc/rc.local

				?

									#!/bin/sh -e

									#

									# rc.local

									#

									# This script is executed at the end of each multiuser runlevel.

									# Make sure that the script will "exit 0" on success or any other

									# value on error.

									#

									# In order to enable or disable this script just change the execution

									# bits.

									#

									# By default this script does nothing.

									exit 0