我正在从Alfresco的php中读取一个文件，然后将其输出到浏览器。唯一的问题是mimetype或文件的扩展名。这是我正在使用的代码：
<?php
ob_start();
//require_once("libs/FirePHPCore/fb.php");
require_once("libs/AlfrescoConnect.php");
$nomeFile = rawurldecode($_GET['nomeFile']);
$urlDownload = $_GET['urlDownload'];
$fileDownloadUrl = AlfrescoConnect::$serverPath. $urlDownload . "&attach=true&alf_ticket=".AlfrescoConnect::getTiket();
fb($fileDownloadUrl);
$cnt = file_get_contents($fileDownloadUrl);
header("Content-type: Application/octet-stream");
header('Cache-Control: must-revalidate');
header('Content-disposition: attachment; filename=' .$nomeFile);
echo($cnt);
exit();
echo("Impossibile trovare il file");
我从get becausa收到文件的名称，我不知道如何从露天获取名称，但我必须以某种方式猜测mimetype。如果我在第一个字符中“回显”$ cnt，则会提到它是一个PDF（例如在屏幕上我看到“％PDF-1.3％âÏÓ20 obj << / Length 3 0 R / Filter / CCITTFaxDecode / DecodeParms << / K 0 / Columns 2480 / Rows 3508 >> / Type / XObject / Subtype / Image / Width 2480 / Height 3508 / BitsPerComponent 1 / ColorSpace / DeviceGray >> stream“所以必须有办法获取mime_tipe从它有一个功能。
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编辑。如果有人是intereste这里是一个类，你可以用来从mime类型获得扩展。 http://www.ustrem.org/en/articles/mime-type-by-extension-en/
使用cURL而不是file_get_contents，然后你可以看到响应头，希望它具有mime类型。
或者你可以尝试使用这个http://www.php.net/manual/en/ref.fileinfo.php或这个不赞成使用的功能http://php.net/manual/en/function.mime-content-type.php
你可以使用finfo::buffer()方法：http://php.net/finfo_buffer。
<?php
$finfo = new finfo(FILEINFO_MIME);
echo $finfo->buffer($cnt) . PHP_EOL;
注意：如果套件比使用面向对象的方法更好，则可以选择使用finfo_buffer过程函数。
您不必猜测（也就是自动检测）MIME类型。
使用$http_response_header检索最后一次file_get_contents调用的标头（或使用http:// wrapper进行的任何调用）。
$contents = file_get_contents("https://www.example.com/");
$pattern = "/^content-type\s*:\s*(.*)$/i";
if (($header = preg_grep($pattern, $http_response_header)) &&
(preg_match($pattern, array_shift(array_values($header)), $match) !== false))
{
$content_type = $match[1];
echo "Content-Type is '$content_type'\n";
}
这是Drupal中filefield_sources模块的curl实现。它可以在任何地方工作：
<?php
// Inspect the remote image
// Check the headers to make sure it exists and is within the allowed size.
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HEADER, TRUE);
curl_setopt($ch, CURLOPT_NOBODY, TRUE);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
curl_setopt($ch, CURLOPT_HEADERFUNCTION, '_filefield_source_remote_parse_header');
// Causes a warning if PHP safe mode is on.
@curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
curl_exec($ch);
$info = curl_getinfo($ch);
curl_close($ch);
/**
* Parse cURL header and record the filename specified in Content-Disposition.
*/
function _filefield_source_remote_parse_header(&$ch, $header) {
if (preg_match('/Content-Disposition:.*?filename="(.+?)"/', $header, $matches)) {
// Content-Disposition: attachment; filename="FILE NAME HERE"
_filefield_source_remote_filename($matches[1]);
}
elseif (preg_match('/Content-Disposition:.*?filename=([^; ]+)/', $header, $matches)) {
// Content-Disposition: attachment; filename=file.ext
_filefield_source_remote_filename($matches[1]);
}
// This is required by cURL.
return strlen($header);
}
/**
* Get/set the remote file name in a static variable.
*/
function _filefield_source_remote_filename($curl_filename = NULL) {
static $filename = NULL;
if (isset($curl_filename)) {
$filename = $curl_filename;
}
return $filename;
}
?>
得到哑剧：
<?php
echo $info['content_type'];
?>
把它放在一个类中：
/**
* Given a string ($data) with a file's contents, guess and return the mime type
*
* Uses the standard unix program /usr/bin/file to handle the magic (pun intended)
*
* @param string $data
*/
public static function get_string_mime_type($data) {
$file_cmd = '/usr/bin/file --brief --mime-type --no-buffer -';
return rtrim(self::exec_write_read($file_cmd, $data));
}
/**
* Executes $cmd, writes to $cmd's stdin, then returns what $cmd wrote to stdout
*/
private static function exec_write_read($cmd, $write, $log_errors = false) {
$descriptorspec = array(
0 => array("pipe", "r"), // stdin is a pipe that $cmd will read from
1 => array("pipe", "w"), // stdout is a pipe that $cmd will write to
2 => array("pipe", "w"), // stderr is a pipe that $cmd will write to
);
$process = proc_open($cmd, $descriptorspec, $pipes);
if (is_resource($process)) {
// $pipes now looks like this:
// 0 => writeable handle connected to child stdin
// 1 => readable handle connected to child stdout
// 2 => readable handle connected to child stderr
fwrite($pipes[0], $write);
fclose($pipes[0]);
$output = stream_get_contents($pipes[1]);
fclose($pipes[1]);
if( $log_errors ){
error_log(stream_get_contents($pipes[2]));
}
fclose($pipes[2]);
// It is important that you close any pipes before calling
// proc_close in order to avoid a deadlock
$exit_code = proc_close($process);
return $output;
}
else {
throw new Exception("Couldn't open $cmd");
}
}
小心 ！不仅要检查mimetype，还要检查恶意代码!!!!!!!!! 细节：PHP: How to get mimeType of a image with file_get_contents