From 1ced5eeaa11b5af8a5a170d041398fa8b38ae5fb Mon Sep 17 00:00:00 2001 From: DarkSun Date: Mon, 25 May 2020 19:21:08 +0800 Subject: [PATCH] =?UTF-8?q?=E9=80=89=E9=A2=98:=2020200525=20How=20to=20Exe?= =?UTF-8?q?cute=20a=20Command=20or=20Script=20at=20Reboot=20or=20Startup?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit sources/tech/20200525 How to Execute a Command or Script at Reboot or Startup.md --- ... Command or Script at Reboot or Startup.md | 159 ++++++++++++++++++ 1 file changed, 159 insertions(+) create mode 100644 sources/tech/20200525 How to Execute a Command or Script at Reboot or Startup.md diff --git a/sources/tech/20200525 How to Execute a Command or Script at Reboot or Startup.md b/sources/tech/20200525 How to Execute a Command or Script at Reboot or Startup.md new file mode 100644 index 0000000000..5d81b593de --- /dev/null +++ b/sources/tech/20200525 How to Execute a Command or Script at Reboot or Startup.md @@ -0,0 +1,159 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (How to Execute a Command or Script at Reboot or Startup) +[#]: via: (https://www.2daygeek.com/execute-run-linux-scripts-command-at-reboot-startup/) +[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/) + +How to Execute a Command or Script at Reboot or Startup +====== + +Well known services on Linux can be added on boot without any problems. + +For example, if you want to add Apache Httpd **[service on boot][1]**, you can do this with the help of the chkconfig and systemctl command. + +Sometimes you need to add a custom script or command or service on boot, and how to do it? + +You can do this using the below three methods. + +In this article, we will show you how to use these methods with examples. + +### Method-1: How to Run Script or Command at Reboot or Startup Using /etc/rc.d/rc.local File + +The **“/etc/rc.local”** file is traditionally executed after all normal computer services have been started at the end of the process of switching to a multiuser runlevel. + +This method also works on the systemd system. + +You need to add the location of your script to the “/etc/rc.d/rc.local” file to run on boot. + +Make sure the file has permission to run. + +``` +# chmod +x /etc/rc.d/rc.local +``` + +To demonstrate this, we are going to create a simple sample script. You can create any script as needed. + +``` +# vi /opt/scripts/run-script-on-boot.sh + +#!/bin/bash +date > /root/on-boot-output.txt +hostname > /root/on-boot-output.txt +``` + +Once the script is ready, set the executable permission. + +``` +# chmod +x /opt/scripts/run-script-on-boot.sh +``` + +Finally add the script to the bottom of the file. + +``` +# vi /etc/rc.d/rc.local + +/opt/scripts/run-script-on-boot.sh +``` + +**[Restart your system][2]** to check this. + +``` +# reboot +``` + +### Method-2: How to Execute a Command or Script at Reboot or Startup Using the crontab + +cron executes scheduled jobs automatically in the backend at a specific time. + +This can be easily accomplished using a special string called **“@reboot”** with **[cron job][3]**. + +@reboot is a special string and allows the user to run any command or script at startup (boot time). + +This example runs the “/opt/scripts/run-script-on-boot.sh” file on the system restart. + +We are going to use the same script as above. + +To do so, just add the following entry in the crontab file. + +``` +# crontab -e + +@reboot /opt/scripts/run-script-on-boot.sh +``` + +Restart your system to check this. + +``` +# reboot +``` + +### Method-3: How to Run a Command or Script at Reboot or Startup Using the systemd service unit + +This method only works on the systemd system. This method is very straightforward. + +We are going to use the same script above to demonstrate this. + +To do so, you need to create a systemd startup script and place it in the **“/etc/systemd/system/”** directory. + +This is our sample systemd startup unit script. + +``` +# vi sample-on-boot-script.service + +[Unit] +Description=Run a Custom Script at Startup +After=default.target + +[Service] +ExecStart=/opt/scripts/run-script-on-boot.sh + +[Install] +WantedBy=default.target +``` + +Once you place the unit script in the systemd location, run the following command to update the systemd configuration files and enable the service. + +``` +# systemctl daemon-reload +# systemctl enable sample-on-boot-script.service +``` + +Restart your system to check this. + +``` +# reboot +``` + +### Bonus Tips: + +If you want to run a script in the background, you need to add the trailing ampersand “&” symbol. + +``` +/Path/To/My_Script & +``` + +If you want to run the command as a different user, use the following format. + +``` +su - $USER -c /Path/To/My_Script +``` + +-------------------------------------------------------------------------------- + +via: https://www.2daygeek.com/execute-run-linux-scripts-command-at-reboot-startup/ + +作者：[Magesh Maruthamuthu][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.2daygeek.com/author/magesh/ +[b]: https://github.com/lujun9972 +[1]: https://www.2daygeek.com/enable-disable-services-on-boot-linux-chkconfig-systemctl-command/ +[2]: https://www.2daygeek.com/6-commands-to-shutdown-halt-poweroff-reboot-the-linux-system/ +[3]: https://www.2daygeek.com/linux-crontab-cron-job-to-schedule-jobs-task/