Answers:
从PHP 5.1.0开始,file_put_contents()支持通过传递流句柄作为$data参数来逐段编写:
file_put_contents("Tmpfile.zip", fopen("http://someurl/file.zip", 'r'));
从手册中:
如果数据 [是第二个参数]是流资源,则该流的剩余缓冲区将被复制到指定文件。这与使用相似
stream_copy_to_stream()。
(感谢Hakre。)
allow_fopen_url Off在php.ini中设置(出于安全性的考虑),您的脚本将被破坏。
                    file_get_contents()如果是这种情况,我认为@idealmachine也将不起作用(请参阅OP)。
                    fopen;防止对图像和其他非纯文本文件产生不利影响。
                    private function downloadFile($url, $path)
{
    $newfname = $path;
    $file = fopen ($url, 'rb');
    if ($file) {
        $newf = fopen ($newfname, 'wb');
        if ($newf) {
            while(!feof($file)) {
                fwrite($newf, fread($file, 1024 * 8), 1024 * 8);
            }
        }
    }
    if ($file) {
        fclose($file);
    }
    if ($newf) {
        fclose($newf);
    }
}
              尝试使用cURL
set_time_limit(0); // unlimited max execution time
$options = array(
  CURLOPT_FILE    => '/path/to/download/the/file/to.zip',
  CURLOPT_TIMEOUT =>  28800, // set this to 8 hours so we dont timeout on big files
  CURLOPT_URL     => 'http://remoteserver.com/path/to/big/file.zip',
);
$ch = curl_init();
curl_setopt_array($ch, $options);
curl_exec($ch);
curl_close($ch);
我不确定,但是我相信CURLOPT_FILE它在提取数据时会写入的选项,即。没有缓冲。
$fh = fopen('/path/to/download/the/file/to.zip', 'w');然后使用fclose($fh);after 关闭curl_close($ch);。并设定CURLOPT_FILE => $fh
                    prodigitalson的答案对我不起作用。我有missing fopen in CURLOPT_FILE 更多细节。
这对我有用,包括本地网址:
function downloadUrlToFile($url, $outFileName)
{   
    if(is_file($url)) {
        copy($url, $outFileName); 
    } else {
        $options = array(
          CURLOPT_FILE    => fopen($outFileName, 'w'),
          CURLOPT_TIMEOUT =>  28800, // set this to 8 hours so we dont timeout on big files
          CURLOPT_URL     => $url
        );
        $ch = curl_init();
        curl_setopt_array($ch, $options);
        curl_exec($ch);
        curl_close($ch);
    }
}
              .php文件中并在目标服务器中运行<html>
<form method="post">
<input name="url" size="50" />
<input name="submit" type="submit" />
</form>
<?php
    // maximum execution time in seconds
    set_time_limit (24 * 60 * 60);
    if (!isset($_POST['submit'])) die();
    // folder to save downloaded files to. must end with slash
    $destination_folder = 'downloads/';
    $url = $_POST['url'];
    $newfname = $destination_folder . basename($url);
    $file = fopen ($url, "rb");
    if ($file) {
      $newf = fopen ($newfname, "wb");
      if ($newf)
      while(!feof($file)) {
        fwrite($newf, fread($file, 1024 * 8 ), 1024 * 8 );
      }
    }
    if ($file) {
      fclose($file);
    }
    if ($newf) {
      fclose($newf);
    }
?>
</html> 
              set_time_limit (24 * 60 * 60);必须放在一个循环中。它在脚本开头没有任何作用。
                    set_time_limit(0); 
$file = file_get_contents('path of your file');
file_put_contents('file.ext', $file);
              在php中使用简单的方法 copy() 
copy($source_url, $local_path_with_file_name);
注意:如果目标文件已经存在,它将被覆盖
注意:您需要为目标文件夹设置权限777。当您下载到本地计算机时,请使用此方法。
特别说明:777是基于Unix的系统中的权限,对所有者,组和所有人都具有完全的读取/写入/执行权限。通常,我们对不需要在Web服务器上公开隐藏的资产授予此权限。示例:images文件夹。
我用这个来下载文件
function cURLcheckBasicFunctions()
{
  if( !function_exists("curl_init") &&
      !function_exists("curl_setopt") &&
      !function_exists("curl_exec") &&
      !function_exists("curl_close") ) return false;
  else return true;
}
/*
 * Returns string status information.
 * Can be changed to int or bool return types.
 */
function cURLdownload($url, $file)
{
  if( !cURLcheckBasicFunctions() ) return "UNAVAILABLE: cURL Basic Functions";
  $ch = curl_init();
  if($ch)
  {
    $fp = fopen($file, "w");
    if($fp)
    {
      if( !curl_setopt($ch, CURLOPT_URL, $url) )
      {
        fclose($fp); // to match fopen()
        curl_close($ch); // to match curl_init()
        return "FAIL: curl_setopt(CURLOPT_URL)";
      }
      if ((!ini_get('open_basedir') && !ini_get('safe_mode')) || $redirects < 1) {
        curl_setopt($ch, CURLOPT_USERAGENT, '"Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.11) Gecko/20071204 Ubuntu/7.10 (gutsy) Firefox/2.0.0.11');
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        //curl_setopt($ch, CURLOPT_REFERER, 'http://domain.com/');
        if( !curl_setopt($ch, CURLOPT_HEADER, $curlopt_header)) return "FAIL: curl_setopt(CURLOPT_HEADER)";
        if( !curl_setopt($ch, CURLOPT_FOLLOWLOCATION, $redirects > 0)) return "FAIL: curl_setopt(CURLOPT_FOLLOWLOCATION)";
        if( !curl_setopt($ch, CURLOPT_FILE, $fp) ) return "FAIL: curl_setopt(CURLOPT_FILE)";
        if( !curl_setopt($ch, CURLOPT_MAXREDIRS, $redirects) ) return "FAIL: curl_setopt(CURLOPT_MAXREDIRS)";
        return curl_exec($ch);
    } else {
        curl_setopt($ch, CURLOPT_USERAGENT, '"Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.11) Gecko/20071204 Ubuntu/7.10 (gutsy) Firefox/2.0.0.11');
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        //curl_setopt($ch, CURLOPT_REFERER, 'http://domain.com/');
        if( !curl_setopt($ch, CURLOPT_FOLLOWLOCATION, false)) return "FAIL: curl_setopt(CURLOPT_FOLLOWLOCATION)";
        if( !curl_setopt($ch, CURLOPT_FILE, $fp) ) return "FAIL: curl_setopt(CURLOPT_FILE)";
        if( !curl_setopt($ch, CURLOPT_HEADER, true)) return "FAIL: curl_setopt(CURLOPT_HEADER)";
        if( !curl_setopt($ch, CURLOPT_RETURNTRANSFER, true)) return "FAIL: curl_setopt(CURLOPT_RETURNTRANSFER)";
        if( !curl_setopt($ch, CURLOPT_FORBID_REUSE, false)) return "FAIL: curl_setopt(CURLOPT_FORBID_REUSE)";
        curl_setopt($ch, CURLOPT_USERAGENT, '"Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.11) Gecko/20071204 Ubuntu/7.10 (gutsy) Firefox/2.0.0.11');
    }
      // if( !curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true) ) return "FAIL: curl_setopt(CURLOPT_FOLLOWLOCATION)";
      // if( !curl_setopt($ch, CURLOPT_FILE, $fp) ) return "FAIL: curl_setopt(CURLOPT_FILE)";
      // if( !curl_setopt($ch, CURLOPT_HEADER, 0) ) return "FAIL: curl_setopt(CURLOPT_HEADER)";
      if( !curl_exec($ch) ) return "FAIL: curl_exec()";
      curl_close($ch);
      fclose($fp);
      return "SUCCESS: $file [$url]";
    }
    else return "FAIL: fopen()";
  }
  else return "FAIL: curl_init()";
}
              PHP 4和5解决方案:
即使单独发送大文件,readfile()也不会出现任何内存问题。如果启用了fopen包装器,则可以将此功能用作URL的文件名。