<?PHP
/**
 * 获取文件MIME类型
 *
 * @param 
 * @author 编程之家 jb51.cc jb51.cc
 **/
$mime = array (
  //applications
  'ai'    => 'application/postscript','eps'   => 'application/postscript','exe'   => 'application/octet-stream','doc'   => 'application/vnd.ms-word','xls'   => 'application/vnd.ms-excel','ppt'   => 'application/vnd.ms-powerpoint','pps'   => 'application/vnd.ms-powerpoint','pdf'   => 'application/pdf','xml'   => 'application/xml','odt'   => 'application/vnd.oasis.opendocument.text','swf'   => 'application/x-shockwave-flash',// archives
  'gz'    => 'application/x-gzip','tgz'   => 'application/x-gzip','bz'    => 'application/x-bzip2','bz2'   => 'application/x-bzip2','tbz'   => 'application/x-bzip2','zip'   => 'application/zip','rar'   => 'application/x-rar','tar'   => 'application/x-tar','7z'    => 'application/x-7z-compressed',// texts
  'txt'   => 'text/plain','PHP'   => 'text/x-PHP','html'  => 'text/html','htm'   => 'text/html','js'    => 'text/javascript','css'   => 'text/css','rtf'   => 'text/rtf','rtfd'  => 'text/rtfd','py'    => 'text/x-python','java'  => 'text/x-java-source','rb'    => 'text/x-ruby','sh'    => 'text/x-shellscript','pl'    => 'text/x-perl','sql'   => 'text/x-sql',// images
  'bmp'   => 'image/x-ms-bmp','jpg'   => 'image/jpeg','jpeg'  => 'image/jpeg','gif'   => 'image/gif','png'   => 'image/png','tif'   => 'image/tiff','tiff'  => 'image/tiff','tga'   => 'image/x-targa','psd'   => 'image/vnd.adobe.photoshop',//audio
  'mp3'   => 'audio/mpeg','mid'   => 'audio/midi','ogg'   => 'audio/ogg','mp4a'  => 'audio/mp4','wav'   => 'audio/wav','wma'   => 'audio/x-ms-wma',// video
  'avi'   => 'video/x-msvideo','dv'    => 'video/x-dv','mp4'   => 'video/mp4','mpeg'  => 'video/mpeg','mpg'   => 'video/mpeg','mov'   => 'video/quicktime','wm'    => 'video/x-ms-wmv','flv'   => 'video/x-flv','mkv'   => 'video/x-matroska'
  );
function _getMimeDetect() {
 if (class_exists('finfo')) {
  return 'finfo';
 } else if (function_exists('mime_content_type')) {
  return 'mime_content_type';
 } else if ( function_exists('exec')) {
  $result = exec('file -ib '.escapeshellarg(__FILE__));
  if ( 0 === strpos($result,'text/x-PHP') OR 0 === strpos($result,'text/x-c++')) {
   return 'linux';
  }
  $result = exec('file -Ib '.escapeshellarg(__FILE__));
  if ( 0 === strpos($result,'text/x-c++')) {
   return 'bsd';
  }
 }
 return 'internal';
}
function _getMimeType($path) {
 global $mime;
 $fmime = _getMimeDetect();
 switch($fmime) {
  case 'finfo':
   $finfo = finfo_open(FILEINFO_MIME);
   if ($finfo) 
    $type = @finfo_file($finfo,$path);
   break;
  case 'mime_content_type':
   $type = mime_content_type($path);
   break;
  case 'linux':
   $type = exec('file -ib '.escapeshellarg($path));
   break;
  case 'bsd':
   $type = exec('file -Ib '.escapeshellarg($path));
   break;
  default:
   $pinfo = pathinfo($path);
   $ext = isset($pinfo['extension']) ? strtolower($pinfo['extension']) : '';
   $type = isset($mime[$ext]) ? $mime[$ext] : 'unkown';
   break;
 }
 $type = explode(';',$type);
 
 //需要加上这段，因为如果使用mime_content_type函数来获取一个不存在的$path时会返回'application/octet-stream'
 if ($fmime != 'internal' AND $type[0] == 'application/octet-stream') {
  $pinfo = pathinfo($path); 
  $ext = isset($pinfo['extension']) ? strtolower($pinfo['extension']) : '';
  if (!empty($ext) AND !empty($mime[$ext])) {
   $type[0] = $mime[$ext];
  }
 }
 
 return $type[0];
}
$path = '1.txt';  //实际上当前路径并不存在1.txt
var_dump(_getMimeType($path));
/*End of PHP*/
/***   代码来自编程之家 jb51.cc（jb51.cc）   ***/