java - 使用PHP exec命令打破无限循环java程序

Question

我有 JDK，我正在尝试执行包含无限循环的 Main.java 程序，并且我想在 java Main.java < input.txt > output.txt 命令进入无限循环时中断它，如果不是的话无限循环不会破坏程序..有什么解决方案吗？遇到麻烦了

<?php

exec('cmd /k c:/wamp/www/javac Main.java 2>&1', $outputAndErrors, $return_value);
for($i=0 ; $i<sizeof($outputAndErrors) ; $i++)
{
    $output1=htmlspecialchars($outputAndErrors[$i],ENT_QUOTES);
    echo "$output1";    
    $flag=1;
}
if(!$flag)
{
    exec('cmd /k c:/wamp/www/java Main.java < input.txt > output.txt', $outputAndErrors, $return_value);
    //want to give timeout but if exec goes to infinite loop than below statement will not executed
}

?>

Answer 1

尝试将其包装在这样的类中(本质上是将其包装在 nohup COMMAND >/dev/null 2>&1 & echo $! 中以获取 pid 并在后台以这种方式使用它)

<?php
    // You may use status(), start(), and stop(). notice that start() method gets called automatically one time.
    $process = new Process('ls -al');

    // or if you got the pid, however here only the status() metod will work.
    $process = new Process();
    $process.setPid(my_pid);
?>

<?php
    // Then you can start/stop/ check status of the job.
    $process.stop();
    $process.start();
    if ($process.status()){
        echo "The process is currently running";
    }else{
        echo "The process is not running.";
    }
?>

<?php
/* An easy way to keep in track of external processes.
* Ever wanted to execute a process in php, but you still wanted to have somewhat controll of the process ? Well.. This is a way of doing it.
* @compability: Linux only. (Windows does not work).
* @author: Peec
*/
class Process{
    private $pid;
    private $command;

    public function __construct($cl=false){
        if ($cl != false){
            $this->command = $cl;
            $this->runCom();
        }
    }
    private function runCom(){
        $command = 'nohup '.$this->command.' > /dev/null 2>&1 & echo $!';
        exec($command ,$op);
        $this->pid = (int)$op[0];
    }

    public function setPid($pid){
        $this->pid = $pid;
    }

    public function getPid(){
        return $this->pid;
    }

    public function status(){
        $command = 'ps -p '.$this->pid;
        exec($command,$op);
        if (!isset($op[1]))return false;
        else return true;
    }

    public function start(){
        if ($this->command != '')$this->runCom();
        else return true;
    }

    public function stop(){
        $command = 'kill '.$this->pid;
        exec($command);
        if ($this->status() == false)return true;
        else return false;
    }
}
?>