如何使用另一个php从php文件中删除行？

如果install.php不在同一目录中，我想从index.php顶部删除这6行。我真的不知道从哪里开始，怎么做

<?php
require ('config.php');
  if (!defined('DATABASE_NAME')) { 
  header('Location: install.php'); exit;
  }
?>

---

您可以创建条件流程，而不是删除：

<?php
    if(file_exists('install.php'))
    {
        require ('config.php');
        if (!defined('DATABASE_NAME')) 
        { 
            header('Location: install.php'); exit;
        }
    }

?>

---

我不太清楚你为什么要删除它们

文件_exists（）可以解决您的问题吗？比如：

if (file_exists("install.php")) {
    // do something
} else {
    // do something else
}

---

在物理删除中删除？或者删除“如果install.php未退出，请不要执行此代码”？试试我的建议。它工作得很好。我已经测试过了。问题是，我不希望index.php以这些行开头，每次都检查install.php是否存在。

<?php
    //SplFileObject (Standard PHP Library) works at PHP 5.1.0+

    $line_to_strip = 6; //be sure that the first 6 lines to be deleted, no empty lines.
    $new_file = new SplFileObject('index.new', 'w');

    foreach (new LimitIterator(new SplFileObject('index.php'), $line_to_strip) as $line)
        $new_file->fwrite($line);    


    //rename the existing index.php file to index.old in order to feel safe
    rename('index.php','index.old');

    //or delete the old index.php file which I do not recommend
    unlink('index.php'); 

    //Since there is no close() function we have to set $new_file null
    //Otherwise you get "file already open and cannot be changed" error
    $new_file = null;

    //rename index.new to index.php
    rename('index.new','index.php');
?>

if (file_exists("install.php")) {
    // do something
} else {
    // do something else
}