A 自帶開機指令碼

/etc/rc.local指令碼是一個ubuntu16.04及其以前的系統中自帶的開機指令碼，在沒有修改之前裡面內容如下。

#!/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
 

B 新增開機指令碼

1,新建個指令碼檔案new_service.sh

#!/bin/bash
# command content
  
exit 0

2,設定許可權

sudo chmod 755 new_service.sh

3,把指令碼放置到啟動目錄下

sudo mv new_service.sh /etc/init.d/

4,將指令碼新增到啟動指令碼

執行如下指令，在這裡90表明一個優先順序，越高表示執行的越晚

cd /etc/init.d/
sudo update-rc.d new_service.sh defaults 90

移除Ubuntu開機指令碼

sudo update-rc.d -f new_service.sh remove