PHP实现远程下载文件到本地

<?php
echo httpcopy("http://www.baidu.com/img/baidu_sylogo1.gif");
  
function httpcopy($url, $file="", $timeout=60) {
  $file = empty($file) ? pathinfo($url,PATHINFO_BASENAME) : $file;
  $dir = pathinfo($file,PATHINFO_DIRNAME);
  !is_dir($dir) && @mkdir($dir,0755,true);
  $url = str_replace(" ","%20",$url);
  
  if(function_exists('curl_init')) {
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
    $temp = curl_exec($ch);
    if(@file_put_contents($file, $temp) && !curl_error($ch)) {
      return $file;
    } else {
      return false;
    }
  } else {
    $opts = array(
      "http"=>array(
      "method"=>"GET",
      "header"=>"",
      "timeout"=>$timeout)
    );
    $context = stream_context_create($opts);
    if(@copy($url, $file, $context)) {
      //$http_response_header
      return $file;
    } else {
      return false;
    }
  }
}
?>