pcntl_exec 和 php 中的 exec 有什么区别？

Question

我已经阅读了 http://us1.php.net/manual/en/function.pcntl-exec.php and http://php.net/manual/en/function.exec.php 上的文档，但我无法真正说出实际区别是什么。

Answer 1

The pcntl_exec() function works exactly like the standard (unix-style) exec() function. It differs from the regular PHP exec() function in that the process calling the pcntl_exec() is replaced with the process that gets called. This is the ideal method for creating children

。在一个简单的示例中（不进行错误检查）：

switch (pcntl_fork()) {
  case 0:
    $cmd = "/path/to/command";
    $args = array("arg1", "arg2");
    pcntl_exec($cmd, $args);
    // the child will only reach this point on exec failure,
    // because execution shifts to the pcntl_exec()ed command
    exit(0);
  default:
    break;
}

// parent continues
echo "I am the parent";

引用自此处的评论： http://us1.php.net/manual/en/function.pcntl-exec.php

pcntl_exec 和 php 中的 exec 有什么区别？

what is the difference between pcntl_exec and exec in php?

php

exec

pcntl