如何检测页面何时使用 PHP 更新 [英] How to detect when a page gets updated with PHP

问题描述

我想知道如何检测页面何时使用 PHP 更新.我在谷歌上研究过东西，但什么也没找到.

I was wondering how to detect when a page gets updated with PHP. I've researched things on Google, but came across nothing.

我想做的是在页面更新时调用特定函数.我将运行一个 cron 作业来运行代码.

What I want to do is call a specific function when a page gets updated. I will be running a cron job in order to run the code.

我想要这样的东西:

if (page updated) {
//functions
}
else
{
//functions
}

如果我不能这样做，那么我至少想知道如何检测页面何时使用 PHP 更新.请帮忙！

If I can't do something like that then I want to at least know how to detect when a page gets updated with PHP. Please help!

推荐答案

使用 file_get_contents() 获取页面的内容，从中创建一个 MD5 散列，并将其与您已有的散列进行比较.我建议将此哈希存储在一个简单的文件中.

Use file_get_contents() to get the page's content, create a MD5 hash from it, and compare it with the hash you already have. I suggest storing this hash in a simple file.

$contents = file_get_contents('http://site.com/page');
$hash     = file_get_contents('hash'); // the text file where the hash is stored
if ($hash == ($pageHash = md5($contents))) {
  // the content is the same
} else {
  // the page has been updated, do whatever you need to do
  // and store the new hash in the file
  $fp = fopen('hash', 'w');
  fwrite($fp, $pageHash);
  fclose($fp);
}

不要忘记设置 allow_url_fopen 到 On.

Don't forget setting allow_url_fopen to On.

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