What is the specific function and advantage of the `nohup` command in the AnQiCMS startup script?

In the daily operation of AnQiCMS, the stability and reliability of the system are the core.As a high-performance content management system built with Go language, AnQiCMS needs to ensure that its core services can run continuously and without interruption.nohupThe command plays a crucial role in the startup script of AnQiCMS, ensuring this and providing us with many conveniences.

When we execute the AnQiCMS executable on a Linux server through an SSH connection, in most cases, once the SSH session is disconnected, the operating system will send a SIGHUP (hang-up) signal to all subprocesses associated with the session.By default, the process receiving the SIGHUP signal will terminate its execution.For a backend service like AnQiCMS, this means the website will stop running, resulting in a service interruption.This is obviously unacceptable.

nohupThe command (full name “no hang up”, i.e. “not hang up”) is designed to solve this core problem.It causes the command to ignore the SIGHUP signal, allowing the process to continue running after the terminal session ends.start.shIn it, we saw such a key line:nohup $BINPATH/$BINNAME >> $BINPATH/running.log 2>&1 &This line of command specifically explains:nohupThe role of it in the AnQiCMS startup process. It will execute the AnQiCMS executable file ($BINPATH/$BINNAMEEnclosed, indicating that the system should not terminate the AnQiCMS process even when the terminal executing the script is closed.

In addition to preventing accidental termination,nohupThe command is closely related to output redirection. In the script,>> $BINPATH/running.log 2>&1Part responsible for appending all standard outputs (stdout) and standard errors (stderr) of the AnQiCMS program torunning.logThis log file contains. This means that both normal operation information of AnQiCMS and any possible errors or warnings will be recorded uniformly. The final&The symbol will execute the entire command in the background, immediately releasing the current terminal, allowing the operator to continue with other tasks without waiting for AnQiCMS to complete.

This startup method brings significant advantages to the operation of AnQiCMS.

Firstly, it ensuresthe persistent operation of the service.Website administrators do not need to worry about AnQiCMS service interruption due to SSH session disconnection, ensuring the website is online 24/7.This is a fundamental and critical guarantee for all enterprises and individuals who rely on AnQiCMS for content publishing and management.

secondly,nohuphas achievedbackground silent operationGreatly improved management efficiency.The AnQiCMS process runs independently in the background and does not occupy the terminal interface.The operation personnel can perform other command-line operations and deploy other services on the same server without being disturbed by the startup or running process of AnQiCMS.

Again, by redirecting all output to a log file (such asrunning.log)nohupWithTroubleshooting and performance monitoringProvided convenience. When AnQiCMS encounters an exception or needs to check its startup process, we can directly view it.running.logThe file from which to obtain detailed runtime logs and error information is crucial for quickly locating problems and analyzing system behavior.

Finally, combining the process check logic commonly included in the startup scriptnohuphelps to builda more robust automated startup mechanism. The script can determine if AnQiCMS is already running, and if not, it will start it throughnohupthe command safely, further improving the reliability and self-recovery ability of the service.

In summary,nohupThe command is the core tool that enables AnQiCMS to run stably and efficiently in a Linux environment.It provides a solid foundation for the continuous availability, convenient management, and problem diagnosis of AnQiCMS by blocking the SIGHUP signal, combining output redirection, and running in the background.

Frequently Asked Questions

How to stop usingnohupThe AnQiCMS service started?

To stop a process throughnohupThe AnQiCMS service has started, you need to find its process ID (PID) and then usekillTerminate the command. Usually, there will be one in the AnQiCMS installation directorystop.shscript, execute this script to safely stop the service. If you need to manually operate, you can do so throughps -ef | grep anqicmsCommand to find the PID of AnQiCMS process (usually displayed in the second column), then usekill -9 <PID>to force terminate the process

2.nohupWhere is the command's output log file?

In the startup script of AnQiCMS,nohupCommands are usually used in conjunction with output redirection to write logs to a specific file. According to the documentation examples, the output log file is usually located in the AnQiCMS installation directory.running.logFor example, if AnQiCMS is installed in/www/wwwroot/anqicmsthen the log file is/www/wwwroot/anqicms/running.log. You can check this file to get the runtime status and detailed information of AnQiCMS.

3. I can manually use it without using the startup scriptnohupCan I start AnQiCMS?

Yes, you can certainly use it manually without using the startup scriptnohupStart AnQiCMS. You just need to go to the installation directory of AnQiCMS and then execute something likenohup ./anqicms >> running.log 2>&1 &Enter the command. But for systematic management and convenience, especially to automatically restore the service after the server restarts, it is strongly recommended that you use the provided startup script (start.sh) in conjunction with the scheduled task (such ascrontabTo start and manage the AnQiCMS service.