远程文件大小，无需下载文件

时间：2010-04-08 18:55:11

标签： php curl

有没有办法在不下载文件的情况下获取远程文件http://my_url/my_file.txt的大小？

14 个答案:

答案 0 :(得分：94)

找到关于此here的内容：

  

这是获得遥控器大小的最佳方式（我发现）   文件。请注意，HEAD请求无法获取请求的实际主体，   他们只是检索标题。因此向资源发出HEAD请求   100MB将花费与HEAD请求相同的时间   资源是1KB。

<?php
/**
 * Returns the size of a file without downloading it, or -1 if the file
 * size could not be determined.
 *
 * @param $url - The location of the remote file to download. Cannot
 * be null or empty.
 *
 * @return The size of the file referenced by $url, or -1 if the size
 * could not be determined.
 */
function curl_get_file_size( $url ) {
  // Assume failure.
  $result = -1;

  $curl = curl_init( $url );

  // Issue a HEAD request and follow any redirects.
  curl_setopt( $curl, CURLOPT_NOBODY, true );
  curl_setopt( $curl, CURLOPT_HEADER, true );
  curl_setopt( $curl, CURLOPT_RETURNTRANSFER, true );
  curl_setopt( $curl, CURLOPT_FOLLOWLOCATION, true );
  curl_setopt( $curl, CURLOPT_USERAGENT, get_user_agent_string() );

  $data = curl_exec( $curl );
  curl_close( $curl );

  if( $data ) {
    $content_length = "unknown";
    $status = "unknown";

    if( preg_match( "/^HTTP\/1\.[01] (\d\d\d)/", $data, $matches ) ) {
      $status = (int)$matches[1];
    }

    if( preg_match( "/Content-Length: (\d+)/", $data, $matches ) ) {
      $content_length = (int)$matches[1];
    }

    // http://en.wikipedia.org/wiki/List_of_HTTP_status_codes
    if( $status == 200 || ($status > 300 && $status <= 308) ) {
      $result = $content_length;
    }
  }

  return $result;
}
?>

用法：

$file_size = curl_get_file_size( "http://stackoverflow.com/questions/2602612/php-remote-file-size-without-downloading-file" );

答案 1 :(得分：60)

试试此代码

function retrieve_remote_file_size($url){
     $ch = curl_init($url);

     curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
     curl_setopt($ch, CURLOPT_HEADER, TRUE);
     curl_setopt($ch, CURLOPT_NOBODY, TRUE);

     $data = curl_exec($ch);
     $size = curl_getinfo($ch, CURLINFO_CONTENT_LENGTH_DOWNLOAD);

     curl_close($ch);
     return $size;
}

答案 2 :(得分：27)

如前所述，方法是从响应标题的Content-Length字段中检索信息。

但是，你应该注意到

  • 您正在探测的服务器不一定实现HEAD方法（！）
  • 当PHP有get_headers()时，完全不需要使用fopen或类似工具来创建HEAD请求（甚至可能不支持），甚至也不需要调用curl库（请记住：K.I.S.S.）

即使您正在探测的服务器不支持HEAD请求，get_headers() 和也会使用K.I.S.S. principle。

所以，这是我的版本（gimmick：返回人类可读的格式化大小; - ））：

要点：https://gist.github.com/eyecatchup/f26300ffd7e50a92bc4d（curl和get_headers版本）
get_headers（） - 版本：

<?php     
/**
 *  Get the file size of any remote resource (using get_headers()), 
 *  either in bytes or - default - as human-readable formatted string.
 *
 *  @author  Stephan Schmitz <eyecatchup@gmail.com>
 *  @license MIT <http://eyecatchup.mit-license.org/>
 *  @url     <https://gist.github.com/eyecatchup/f26300ffd7e50a92bc4d>
 *
 *  @param   string   $url          Takes the remote object's URL.
 *  @param   boolean  $formatSize   Whether to return size in bytes or formatted.
 *  @param   boolean  $useHead      Whether to use HEAD requests. If false, uses GET.
 *  @return  string                 Returns human-readable formatted size
 *                                  or size in bytes (default: formatted).
 */
function getRemoteFilesize($url, $formatSize = true, $useHead = true)
{
    if (false !== $useHead) {
        stream_context_set_default(array('http' => array('method' => 'HEAD')));
    }
    $head = array_change_key_case(get_headers($url, 1));
    // content-length of download (in bytes), read from Content-Length: field
    $clen = isset($head['content-length']) ? $head['content-length'] : 0;

    // cannot retrieve file size, return "-1"
    if (!$clen) {
        return -1;
    }

    if (!$formatSize) {
        return $clen; // return size in bytes
    }

    $size = $clen;
    switch ($clen) {
        case $clen < 1024:
            $size = $clen .' B'; break;
        case $clen < 1048576:
            $size = round($clen / 1024, 2) .' KiB'; break;
        case $clen < 1073741824:
            $size = round($clen / 1048576, 2) . ' MiB'; break;
        case $clen < 1099511627776:
            $size = round($clen / 1073741824, 2) . ' GiB'; break;
    }

    return $size; // return formatted size
}

用法：

$url = 'http://download.tuxfamily.org/notepadplus/6.6.9/npp.6.6.9.Installer.exe';
echo getRemoteFilesize($url); // echoes "7.51 MiB"

附加说明： Content-Length标头是可选的。因此，作为一般解决方案它不是防弹！

答案 3 :(得分：14)

不确定。制作仅限标头的请求，并查找Content-Length标头。

答案 4 :(得分：7)

Php函数get_headers()适用于检查内容长度为

$headers = get_headers('http://example.com/image.jpg', TRUE);
$filesize = $headers['content-length'];

详细信息：PHP Function get_headers()

答案 5 :(得分：6)

我不确定，但你不能使用get_headers函数吗？

$url     = 'http://example.com/dir/file.txt';
$headers = get_headers($url, true);

if ( isset($headers['Content-Length']) ) {
   $size = 'file size:' . $headers['Content-Length'];
}
else {
   $size = 'file size: unknown';
}

echo $size;

答案 6 :(得分：3)

最简单，最有效的实施方式：

function remote_filesize($url, $fallback_to_download = false)
{
    static $regex = '/^Content-Length: *+\K\d++$/im';
    if (!$fp = @fopen($url, 'rb')) {
        return false;
    }
    if (isset($http_response_header) && preg_match($regex, implode("\n", $http_response_header), $matches)) {
        return (int)$matches[0];
    }
    if (!$fallback_to_download) {
        return false;
    }
    return strlen(stream_get_contents($fp));
}

答案 7 :(得分：2)

由于这个问题已被标记为“php”和“curl”，我假设你知道如何在PHP中使用Curl。

如果您设置了curl_setopt(CURLOPT_NOBODY, TRUE)，那么您将发出一个HEAD请求，并且可能会检查响应的“Content-Length”标头，该标头只是标题。

答案 8 :(得分：2)

尝试使用以下函数获取远程文件大小

function remote_file_size($url){
    $head = "";
    $url_p = parse_url($url);

    $host = $url_p["host"];
    if(!preg_match("/[0-9]*\.[0-9]*\.[0-9]*\.[0-9]*/",$host)){

        $ip=gethostbyname($host);
        if(!preg_match("/[0-9]*\.[0-9]*\.[0-9]*\.[0-9]*/",$ip)){

            return -1;
        }
    }
    if(isset($url_p["port"]))
    $port = intval($url_p["port"]);
    else
    $port    =    80;

    if(!$port) $port=80;
    $path = $url_p["path"];

    $fp = fsockopen($host, $port, $errno, $errstr, 20);
    if(!$fp) {
        return false;
        } else {
        fputs($fp, "HEAD "  . $url  . " HTTP/1.1\r\n");
        fputs($fp, "HOST: " . $host . "\r\n");
        fputs($fp, "User-Agent: http://www.example.com/my_application\r\n");
        fputs($fp, "Connection: close\r\n\r\n");
        $headers = "";
        while (!feof($fp)) {
            $headers .= fgets ($fp, 128);
            }
        }
    fclose ($fp);

    $return = -2;
    $arr_headers = explode("\n", $headers);
    foreach($arr_headers as $header) {

        $s1 = "HTTP/1.1";
        $s2 = "Content-Length: ";
        $s3 = "Location: ";

        if(substr(strtolower ($header), 0, strlen($s1)) == strtolower($s1)) $status = substr($header, strlen($s1));
        if(substr(strtolower ($header), 0, strlen($s2)) == strtolower($s2)) $size   = substr($header, strlen($s2));
        if(substr(strtolower ($header), 0, strlen($s3)) == strtolower($s3)) $newurl = substr($header, strlen($s3));  
    }

    if(intval($size) > 0) {
        $return=intval($size);
    } else {
        $return=$status;
    }

    if (intval($status)==302 && strlen($newurl) > 0) {

        $return = remote_file_size($newurl);
    }
    return $return;
}

答案 9 :(得分：1)

这里的大多数答案都使用CURL或基于读取标题。但在某些情况下，您可以使用更简单的解决方案。考虑filesize()'s docs on PHP.net上的注释。你会发现有一个提示：“从PHP 5.0.0开始，这个函数也可以用于一些URL包装器。请参考Supported Protocols and Wrappers来确定哪些包装器支持stat（）系列功能< / EM>”。

因此，如果你的服务器和PHP解析器配置正确，你可以简单地使用filesize()函数，用完整的URL提供它，指向你想要获得的大小的远程文件，并让PHP执行所有的魔法。

答案 10 :(得分：1)

这是另一种适用于不支持HEAD请求的服务器的方法。

它使用cURL来请求带有HTTP范围标题的内容，询问文件的第一个字节。

如果服务器支持范围请求（大多数媒体服务器将），那么它将收到具有资源大小的响应。

如果服务器没有响应字节范围，它将查找内容长度标题以确定长度。

如果在范围或内容长度标题中找到大小，则传输将中止。如果未找到大小且函数开始读取响应主体，则传输将中止。

如果HEAD请求导致405方法不支持响应，这可能是一种补充方法。

/**
 * Try to determine the size of a remote file by making an HTTP request for
 * a byte range, or look for the content-length header in the response.
 * The function aborts the transfer as soon as the size is found, or if no
 * length headers are returned, it aborts the transfer.
 *
 * @return int|null null if size could not be determined, or length of content
 */
function getRemoteFileSize($url)
{
    $ch = curl_init($url);

    $headers = array(
        'Range: bytes=0-1',
        'Connection: close',
    );

    $in_headers = true;
    $size       = null;

    curl_setopt($ch, CURLOPT_HEADER, 1);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2450.0 Iron/46.0.2450.0');
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
    curl_setopt($ch, CURLOPT_VERBOSE, 0); // set to 1 to debug
    curl_setopt($ch, CURLOPT_STDERR, fopen('php://output', 'r'));

    curl_setopt($ch, CURLOPT_HEADERFUNCTION, function($curl, $line) use (&$in_headers, &$size) {
        $length = strlen($line);

        if (trim($line) == '') {
            $in_headers = false;
        }

        list($header, $content) = explode(':', $line, 2);
        $header = strtolower(trim($header));

        if ($header == 'content-range') {
            // found a content-range header
            list($rng, $s) = explode('/', $content, 2);
            $size = (int)$s;
            return 0; // aborts transfer
        } else if ($header == 'content-length' && 206 != curl_getinfo($curl, CURLINFO_HTTP_CODE)) {
            // found content-length header and this is not a 206 Partial Content response (range response)
            $size = (int)$content;
            return 0;
        } else {
            // continue
            return $length;
        }
    });

    curl_setopt($ch, CURLOPT_WRITEFUNCTION, function($curl, $data) use ($in_headers) {
        if (!$in_headers) {
            // shouldn't be here unless we couldn't determine file size
            // abort transfer
            return 0;
        }

        // write function is also called when reading headers
        return strlen($data);
    });

    $result = curl_exec($ch);
    $info   = curl_getinfo($ch);

    return $size;
}

用法：

$size = getRemoteFileSize('http://example.com/video.mp4');
if ($size === null) {
    echo "Could not determine file size from headers.";
} else {
    echo "File size is {$size} bytes.";
}

答案 11 :(得分：1)

一线最佳解决方案：

echo array_change_key_case(get_headers("http://.../file.txt",1))['content-length'];

php太巧妙了

function urlsize($url):int{
   return array_change_key_case(get_headers($url,1))['content-length'];
}

echo urlsize("http://.../file.txt");

答案 12 :(得分：1)

要覆盖HTTP / 2请求，https://stackoverflow.com/a/2602624/2380767此处提供的功能需要稍作更改：

<?php
/**
 * Returns the size of a file without downloading it, or -1 if the file
 * size could not be determined.
 *
 * @param $url - The location of the remote file to download. Cannot
 * be null or empty.
 *
 * @return The size of the file referenced by $url, or -1 if the size
 * could not be determined.
 */
function curl_get_file_size( $url ) {
  // Assume failure.
  $result = -1;

  $curl = curl_init( $url );

  // Issue a HEAD request and follow any redirects.
  curl_setopt( $curl, CURLOPT_NOBODY, true );
  curl_setopt( $curl, CURLOPT_HEADER, true );
  curl_setopt( $curl, CURLOPT_RETURNTRANSFER, true );
  curl_setopt( $curl, CURLOPT_FOLLOWLOCATION, true );
  curl_setopt( $curl, CURLOPT_USERAGENT, get_user_agent_string() );

  $data = curl_exec( $curl );
  curl_close( $curl );

  if( $data ) {
    $content_length = "unknown";
    $status = "unknown";

    if( preg_match( "/^HTTP\/1\.[01] (\d\d\d)/", $data, $matches ) ) {
      $status = (int)$matches[1];
    } elseif( preg_match( "/^HTTP\/2 (\d\d\d)/", $data, $matches ) ) {
      $status = (int)$matches[1];
    }

    if( preg_match( "/Content-Length: (\d+)/", $data, $matches ) ) {
      $content_length = (int)$matches[1];
    } elseif( preg_match( "/content-length: (\d+)/", $data, $matches ) ) {
        $content_length = (int)$matches[1];
    }

    // http://en.wikipedia.org/wiki/List_of_HTTP_status_codes
    if( $status == 200 || ($status > 300 && $status <= 308) ) {
      $result = $content_length;
    }
  }

  return $result;
}
?>

答案 13 :(得分：0)

试试这个：我用它并取得了不错的结果。

    function getRemoteFilesize($url)
{
    $file_headers = @get_headers($url, 1);
    if($size =getSize($file_headers)){
return $size;
    } elseif($file_headers[0] == "HTTP/1.1 302 Found"){
        if (isset($file_headers["Location"])) {
            $url = $file_headers["Location"][0];
            if (strpos($url, "/_as/") !== false) {
                $url = substr($url, 0, strpos($url, "/_as/"));
            }
            $file_headers = @get_headers($url, 1);
            return getSize($file_headers);
        }
    }
    return false;
}

function getSize($file_headers){

    if (!$file_headers || $file_headers[0] == "HTTP/1.1 404 Not Found" || $file_headers[0] == "HTTP/1.0 404 Not Found") {
        return false;
    } elseif ($file_headers[0] == "HTTP/1.0 200 OK" || $file_headers[0] == "HTTP/1.1 200 OK") {

        $clen=(isset($file_headers['Content-Length']))?$file_headers['Content-Length']:false;
        $size = $clen;
        if($clen) {
            switch ($clen) {
                case $clen < 1024:
                    $size = $clen . ' B';
                    break;
                case $clen < 1048576:
                    $size = round($clen / 1024, 2) . ' KiB';
                    break;
                case $clen < 1073741824:
                    $size = round($clen / 1048576, 2) . ' MiB';
                    break;
                case $clen < 1099511627776:
                    $size = round($clen / 1073741824, 2) . ' GiB';
                    break;
            }
        }
        return $size;

    }
    return false;
}

现在，测试如下：

echo getRemoteFilesize('http://mandasoy.com/wp-content/themes/spacious/images/plain.png').PHP_EOL;
echo getRemoteFilesize('http://bookfi.net/dl/201893/e96818').PHP_EOL;
echo getRemoteFilesize('https://stackoverflow.com/questions/14679268/downloading-files-as-attachment-filesize-incorrect').PHP_EOL;

结果：

24.82 KiB

912 KiB

101.85 KiB

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