How to get PHP script to run in the background and terminate the process via Enter?

Tips for getting PHP scripts to run in the background and terminate gracefully

This article discusses how to make PHP scripts run in the background and provides a more convenient termination method than ctrl c , that is, end the process by pressing Enter. It should be noted that PHP itself is not a daemon manager, which is different from tools such as Workerman. Tools such as Workerman usually have built-in background operation and process management mechanisms. For ordinary PHP scripts, we need to use system commands and some skills.

First, suppose we have a PHP script called s.php , with its core loop as follows:

 <?php cli_set_process_title(&#39;queue-server&#39;);

while (true) {
    // ...Your business logic...
}

Running php s.php directly will cause the script to run in the terminal foreground. To make it run in the background and be able to terminate with the Enter key, we can use the following method:

Method 1: Combining nohup and screen or tmux

The nohup command can ignore the hangup signal and make the script continue to run in the background. But it lacks a convenient termination mechanism. screen or tmux is a terminal multiplexer that allows you to work in multiple terminal sessions and can easily manage background processes.

1. Start the script using screen or tmux :

    screen -dmS queue-server nohup php s.php 2>&1 &

   This line of command will start a screen session called queue-server in the background and run nohup php s.php 2>&1 & in it. -dmS parameters represent separation mode, display name and create session respectively. 2>&1 redirects the standard error to the standard output.

2. Terminate script:

   a. Use screen -r queue-server to reconnect to the queue-server session. b. Press Ctrl a in the session and then press k (or Ctrl c ) to terminate the process.

   The usage method of tmux is similar, except that the commands are slightly different, please refer to the documentation of tmux .

Method 2: Use PHP's pcntl extension (more advanced, you need to understand process management)

PHP's pcntl extension provides process control functions, allowing more granular process management to be implemented inside PHP scripts. This requires more in-depth programming knowledge, but allows for more flexible control. Here is a simple example that listens for standard input and terminates the process when the Enter key is received:

 <?php cli_set_process_title(&#39;queue-server&#39;);

$stdin = fopen(&#39;php://stdin&#39;, &#39;r&#39;);

declare(ticks=1);
register_tick_function(function() use ($stdin){
    $line = fgets($stdin);
    if ($line !== false && trim($line) === "") {
        exit(0);
    }
});

while (true) {
    // ...Your business logic...
    usleep(100000); // Avoid excessive CPU usage}

This script listens to standard input and ends the process when a blank line (Enter key) is detected. It should be noted that pcntl extension needs to be enabled during PHP installation.

Which method to choose depends on your needs and skill level. For simple background operation and termination, Method 1 is simpler and easier to use; while Method 2 provides more granular control, but requires a deeper understanding. Remember, no matter which method, exceptions and errors of scripts should be properly handled to ensure the stability and reliability of the scripts.

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