PHP process signal handling

This article mainly introduces PHP process signal processing, which has certain reference value. Now I share it with everyone. Friends in need can refer to it

<?php
while (1)
 {
     echo "I am doing something important\n";    
     echo "If i am interruptted, the data will be corrupted\n";    
     echo "Be careful\n";    
     echo "\n\n";
    sleep(5);
}

Assumptions Now we have the above PHP script. We want the script to output a piece of information and end the script when it receives process signals such as SIGINT and SIGTERM. How to achieve this?

Just use the pcntl_signal and pcntl_signal_dispatch functions (note that PHP needs to install the pcntl extension to use these two functions), see the code:

<?php/**
 * 信号ID和信号名称对应关系，没注释掉的信号都是可以通过pcntl_signal函数注册的
 */
 $GLOBALS[&#39;G_SIG_MAP&#39;] = array(
     1 => &#39;SIGHUP&#39;,    
     2 => &#39;SIGINT&#39;,    
     3 => &#39;SIGQUIT&#39;,    
     4 => &#39;SIGILL&#39;,    
     5 => &#39;SIGTRAP&#39;,    
     6 => &#39;SIGABRT&#39;,    
     7 => &#39;SIGEMT&#39;,    
     8 => &#39;SIGFPE&#39;,    
     //9 => &#39;SIGKILL&#39;,
    10 => &#39;SIGBUS&#39;,    
    11 => &#39;SIGSEGV&#39;,    
    12 => &#39;SIGSYS&#39;,    
    13 => &#39;SIGPIPE&#39;,    
    14 => &#39;SIGALRM&#39;,    
    15 => &#39;SIGTERM&#39;,    
    16 => &#39;SIGURG&#39;,    
    //17 => &#39;SIGSTOP&#39;,
    18 => &#39;SIGTSTP&#39;,    
    19 => &#39;SIGCONT&#39;,    
    20 => &#39;SIGCHLD&#39;,    
    21 => &#39;SIGTTIN&#39;,    
    22 => &#39;SIGTTOU&#39;,    
    23 => &#39;SIGIO&#39;,    
    24 => &#39;SIGXCPU&#39;,    
    25 => &#39;SIGXFSZ&#39;,    
    26 => &#39;SIGVTALRM&#39;,    
    27 => &#39;SIGPROF&#39;,    
    28 => &#39;SIGWINCH&#39;,    
    29 => &#39;SIGINFO&#39;,    
    30 => &#39;SIGUSR1&#39;,    
    31 => &#39;SIGUSR2&#39;,
);
/**
 * 进程信号处理函数
 * @param int $signo 信号ID
 */function signalHandler($signo) {
    if (isset($GLOBALS[&#39;G_SIG_MAP&#39;][$signo])) {  
    echo "Caught signal {$GLOBALS[&#39;G_SIG_MAP&#39;][$signo]}, exit\n";
    } else {      
              echo "Caught unknown signal:$signo";
    }    
    exit();
}foreach ($GLOBALS[&#39;G_SIG_MAP&#39;] as $id => $name) {
    pcntl_signal($id, &#39;signalHandler&#39;);
}while (1) {
                echo "I am doing something important\n";    
                echo "If i am interruptted, the data will be corrupted\n";    
                echo "Be careful\n";    echo "\n\n";
    pcntl_signal_dispatch(); // 此函数调用必须放在循环体内
    sleep(5);
}

Execute this in the linux shell script, and then use the kill -2 script process ID command to send a signal to the process. The script outputs the information normally and exits.

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Detailed explanation of PHP inter-process communication

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