php文件上传经典代码
function fileupload( $resourcetype, $currentfolder, $scommand )
{
 if (!isset($_files)) {
  global $_files;
 }
 $serrornumber = '0' ;
 $sfilename = '' ;
 if ( isset( $_files['newfile'] ) && !is_null( $_files['newfile']['tmp_name'] ) )
 {
  global $config ;
  $ofile = $_files['newfile'] ;
  // map the virtual path to the local server path.
  $sserverdir = servermapfolder( $resourcetype, $currentfolder, $scommand ) ;
  // get the uploaded file name.
  $sfilename = $ofile['name'] ;
  $sfilename = sanitizefilename( $sfilename ) ;
  $soriginalfilename = $sfilename ;
  // get the extension.
  $sextension = substr( $sfilename, ( strrpos($sfilename, '.') + 1 ) ) ;
  $sextension = strtolower( $sextension ) ;
  if ( isset( $config['secureimageuploads'] ) )
  {
   if ( ( $isimagevalid = isimagevalid( $ofile['tmp_name'], $sextension ) ) === false )
   {
    $serrornumber = '202' ;
   }
  }
  if ( isset( $config['htmlextensions'] ) )
  {
   if ( !ishtmlextension( $sextension, $config['htmlextensions'] ) &&
    ( $detecthtml = detecthtml( $ofile['tmp_name'] ) ) === true )
   {
    $serrornumber = '202' ;
   }
  }
  // check if it is an allowed extension.
  if ( !$serrornumber && isallowedext( $sextension, $resourcetype ) )
  {
   $icounter = 0 ;
   while ( true )
   {
    $sfilepath = $sserverdir . $sfilename ;
    if ( is_file( $sfilepath ) )
    {
     $icounter++ ;
     $sfilename = removeextension( $soriginalfilename ) . '(' . $icounter . ').' . $sextension ;
     $serrornumber = '201' ;
    }
    else
    {
     move_uploaded_file( $ofile['tmp_name'], $sfilepath ) ;
     if ( is_file( $sfilepath ) )
     {
      if ( isset( $config['chmodonupload'] ) && !$config['chmodonupload'] )
      {
       break ;
      }
      $permissions = 0777;
      if ( isset( $config['chmodonupload'] ) && $config['chmodonupload'] )
      {
       $permissions = $config['chmodonupload'] ;
      }
      $oldumask = umask(0) ;
      chmod( $sfilepath, $permissions ) ;
      umask( $oldumask ) ;
     }
     break ;
    }
   }
   if ( file_exists( $sfilepath ) )
   {
    //previous checks failed, try once again
    if ( isset( $isimagevalid ) && $isimagevalid === -1 && isimagevalid( $sfilepath, $sextension ) === false )
    {
     @unlink( $sfilepath ) ;
     $serrornumber = '202' ;
    }
    else if ( isset( $detecthtml ) && $detecthtml === -1 && detecthtml( $sfilepath ) === true )
    {
     @unlink( $sfilepath ) ;
     $serrornumber = '202' ;
    }
   }
  }
  else
   $serrornumber = '202' ;
 }
 else
  $serrornumber = '202' ;
$sfileurl = combinepaths( getresourcetypepath( $resourcetype, $scommand ) , $currentfolder ) ;
 $sfileurl = combinepaths( $sfileurl, $sfilename ) ;
 senduploadresults( $serrornumber, $sfileurl, $sfilename ) ;
 exit ;