有没有一种方法可以获取远程文件http://my_url/my_file.txt的大小而无需下载文件?
有没有一种方法可以获取远程文件http://my_url/my_file.txt的大小而无需下载文件?
Answers:
在这里找到有关此的一些信息:
这是(我发现)获取远程文件大小的最佳方法。请注意,HEAD请求没有获得请求的实际主体,它们只是检索标头。因此,对100MB的资源进行HEAD请求所花费的时间与对1KB的资源进行HEAD请求所花费的时间相同。
<?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:
$file_size = curl_get_file_size( "http://stackoverflow.com/questions/2602612/php-remote-file-size-without-downloading-file" );
curl_getinfo
像@macki建议的那样使用会更好吗?
get_user_agent_string()
未定义,这对我不起作用。删除整行使整个工作正常。
http://www.dailymotion.com/rss/user/dialhainaut/
参见SO:stackoverflow.com/questions/36761377/…–
试试这个代码
function retrieve_remote_file_size($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 $size;
}
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
。
CURLOPT_FOLLOWLOCATION
设置为true。
如前所述,方法是从响应标头的Content-Length
field检索信息。
但是,您应该注意
fopen
当PHP具有get_headers()
(记住:KISS)时,绝对不需要使用或类似方法手动创建HEAD请求(再次可能甚至不支持它),甚至调用curl库。即使您要探测的服务器不支持HEAD请求,也可以get_headers()
遵循KISS原则, 并且可以使用。
所以,这是我的版本(gi头: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,它不是防弹的!
Content-Length
是可选的,但这是不下载文件即可获取文件大小的唯一方法-get_headers
也是获取的最佳方法content-length
。
stream_context_create
创建一个单独的上下文中使用的调用get_headers
(7.1+)。
PHP功能get_headers()
对我来说检查内容长度为
$headers = get_headers('http://example.com/image.jpg', 1);
$filesize = $headers['Content-Length'];
有关更多详细信息:PHP函数get_headers()
我不确定,但是您不能使用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 $size;
一线最佳解决方案:
echo array_change_key_case(get_headers("http://.../file.txt",1))['content-length'];
php太delicius
function urlsize($url):int{
return array_change_key_case(get_headers($url,1))['content-length'];
}
echo urlsize("http://.../file.txt");
最简单,最有效的实现:
function remote_filesize($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));
}
Content-Length
标题。$fp
不需要显式关闭;它会在过期时自动释放。php.net/manual/en/language.types.resource.php
nc -l localhost 8080
*close
功能在现代PHP中不是必需的。它们来自两个历史原因:实现限制和模仿C语言。
尝试以下功能获取远程文件大小
function remote_file_size($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 $return;
}
这是另一种适用于不支持服务器的方法 HEAD
请求的。
它使用cURL来请求内容,并带有一个HTTP范围标头,要求文件的第一个字节。
如果服务器支持范围请求(大多数媒体服务器将支持),则它将接收到具有资源大小的响应。
如果服务器不响应字节范围,则它将寻找内容长度标头来确定长度。
如果在范围或内容长度标头中找到大小,则传输将中止。如果找不到大小,并且函数开始读取响应正文,则传输中止。
如果HEAD
请求导致405
方法不支持的响应,则这可能是一种补充方法。
/**
* Try to determine the size of a remote file by making an HTTP request for
* a byte range, or look for the content-length header in the response.
* The function aborts the transfer as soon as the size is found, or if no
* length headers are returned, it aborts the transfer.
*
* @return int|null null if size could not be determined, or length of content
*/
function getRemoteFileSize($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 {$size} bytes.";
}
Content-Length
不可用。
此处的大多数答案都使用CURL或基于阅读标头。但是在某些情况下,您可以使用更简便的解决方案。考虑一下filesize()
PHP.net上有关文档的注释。您会发现一条提示:“从PHP 5.0.0开始,此功能还可以与某些URL包装器一起使用。请参阅支持的协议和包装器,以确定哪些包装器支持stat()系列功能”。
因此,如果正确配置了服务器和PHP解析器,则可以简单地使用filesize()
function,将其提供完整的URL,指向一个远程文件,指定要获取的大小,然后让PHP发挥所有作用。
试试看:我用它并取得了良好的效果。
function getRemoteFilesize($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,像这样测试:
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('/programming/14679268/downloading-files-as-attachment-filesize-incorrect').PHP_EOL;
结果:
24.82 KiB
912 KiB
101.85 KiB
为了涵盖HTTP / 2请求,此处的https://stackoverflow.com/a/2602624/2380767提供的功能需要进行一些更改:
<?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;
}
?>