php使用curl代理实现抓取数据的方法

<?php
define ( 'IS_PROXY', true ); //是否启用代理
function async_get_url($url_array, $wait_usec = 0)
{
  if (!is_array($url_array))
    return false;
  $wait_usec = intval($wait_usec);
  $data  = array();
  $handle = array();
  $running = 0;
  $mh = curl_multi_init(); // 开启多线程
  $i = 0;
  foreach($url_array as $url) {
    $ch = curl_init();
    if (IS_PROXY) {
    //以下代码设置代理服务器
    //代理服务器地址http://www.cnproxy.com/proxy1.html !!Hong Kong, China的速度比较好
    curl_setopt ($ch, CURLOPT_PROXY,'110.4.12.170:80' );
    }
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); // return don't print
    curl_setopt($ch, CURLOPT_TIMEOUT, 30); //设置超时时间
    curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)');
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1); // 302 redirect
    curl_setopt($ch, CURLOPT_MAXREDIRS, 7); //HTTp定向级别
    curl_multi_add_handle($mh, $ch); // 把 curl resource 放进 multi curl handler 里
    $handle[$i++] = $ch;
  }
  /* 执行 */
  do {
    $mrc = curl_multi_exec($mh, $running);
    if ($wait_usec > 0) /* 每个 connect 要间隔多久 */
      usleep($wait_usec); // 250000 = 0.25 sec
  } while ($mrc == CURLM_CALL_MULTI_PERFORM);
  while ($running && $mrc == CURLM_OK) {
    if (curl_multi_select($mh) != -1) {
      do {
        $mrc = curl_multi_exec($mh, $running);
      } while ($mrc == CURLM_CALL_MULTI_PERFORM);
    }
  }
  /* 读取资料 */
  foreach($handle as $i => $ch) {
    $content = curl_multi_getcontent($ch);
    $data[$i] = (curl_errno($ch) == 0) ? $content : false;
  }
  /* 移除 handle*/
  foreach($handle as $ch) {
    curl_multi_remove_handle($mh, $ch);
  }
  curl_multi_close($mh);
  return $data;
}
$urls = array('http://map.baidu.com');
$re = async_get_url($urls);
echo $re[0];
?>