shell_exec导致无限循环

Question

I have a problem with shell_exec. I try to run the other php file in a separate thread, according to this answer: https://stackoverflow.com/a/222445/1999929 I have this very-very simple code:

<?php
     $realpath = realpath("./second.php");
     file_put_contents("./log.txt","
First php running!
",FILE_APPEND);
     shell_exec("php $realpath > /dev/null 2>/dev/null &");
?>

I need this because i want to use this file for a dropbox webhook link, and it has to give a response in 10 seconds, while processing the changed files sometimes takes more time. So this file has to tell te other to run, and give a response, while not waiting for the other to finish.

When shell_exec is used in the code, the text is outputted infinite times in the file, without it its working fine, but i need to call the other file somehow.

EDIT - I tried exec() too, because the answer above used it instead of shell_exec, results are the same.

Answer 1

The issue is with the ENV, something in the ENV conflict with the second call to PHP making PHP calling infinite times the second file. This will create a fork bomb.

But if you just reset the $env array to an empty array the second file will be called correctly.

Neither shell_exec() or exec() all you to manipulate $ENV. You'll need to use "proc_open":

resource proc_open ( $cmd , $descriptorspec , &$pipes [, $cwd [, $env]] )

So:

<?php
     $env = array();
     $realpath = realpath("./second.php");
     file_put_contents("./log.txt","
First php running!
",FILE_APPEND);
     proc_open(
        "php $realpath > /dev/null 2>/dev/null &",
        $descriptorspec,
        $pipes,
        __DIR__,
        $env
     );
?>