PHP checks whether the content has external links

This article mainly introduces the method of PHP checking whether there are external links in a string, and involves PHP's regular matching skills for strings. I hope to be helpful.

The specific implementation method is as follows:

/**
 * is_external_link 检测字符串是否包含外链
 * @param string $text 文字
 * @param string $host 域名
 * @return boolean    false 有外链 true 无外链
 * /
function all_external_link($text = '', $host = '') {
  if (empty($host)) $host = $_SERVER['HTTP_HOST'];
  $reg = '/http(?:s?):\/\/((?:[A-za-z0-9-]+\.)+[A-za-z]{2,4})/';
  preg_match_all($reg, $text, $data);
  $math = $data[1];
  foreach ($math as $value) {
    if($value != $host) return false;
  }
  return true;
}

Related recommendations:

About php Detailed introduction to string functions

Summary of common functions used in PHP regular expressions

PHP regular expression efficiency greedy, non-greedy and backtracking analysis (recommended)

The above is the detailed content of PHP checks whether the content has external links. For more information, please follow other related articles on the PHP Chinese website!