php结合正则批量抓取网页中邮箱地址

<?php
  $url='https://www.jb51.net'; //要采集的网址 
  $content=file_get_contents($url);
  //echo $content;
  function getEmail($str) {
  //$pattern = "/([a-z0-9]*[-_\.]?[a-z0-9]+)*@([a-z0-9]*[-_]?[a-z0-9]+)+[\.][a-z]{2,3}([\.][a-z]{2})?/i";
  $pattern = "/([a-z0-9\-_\.]+@[a-z0-9]+\.[a-z0-9\-_\.]+)/";
  preg_match_all($pattern,$str,$emailArr);
 
  return $emailArr[0];
  }
  print_r( getEmail($content));
  ?>

<?php 
$url='https://www.jb51.net'; //当页已留邮箱
$content=file_get_contents($url);             //获取页面内容
function getEmail($str) {                 //匹配邮箱内容
$pattern = "/([a-z0-9\-_\.]+@[a-z0-9]+\.[a-z0-9\-_\.]+)/"; 
preg_match_all($pattern,$str,$emailArr); 
return $emailArr[0]; 
} 
print_r( getEmail($content)); 
?>