php判断文件上传图片格式的实例详解

 $type  = $_FILES['image']['tmp_name'];//文件名 //$type  = $this->getImagetype( $type );  $filetype = ['jpg', 'jpeg', 'gif', 'bmp', 'png']; if (! in_array($type, $filetype)) {   return "不是图片类型"; ｝

 //*判断图片上传格式是否为图片 return返回文件后缀 public function getImagetype($filename) {  $file = fopen($filename, 'rb');  $bin = fread($file, 2); //只读2字节  fclose($file);  $strInfo = @unpack('C2chars', $bin);  $typeCode = intval($strInfo['chars1'].$strInfo['chars2']);  // dd($typeCode);  $fileType = '';  switch ($typeCode) {   case 255216:    $fileType = 'jpg';    break;   case 7173:    $fileType = 'gif';    break;   case 6677:    $fileType = 'bmp';    break;   case 13780:    $fileType = 'png';    break;   default:    $fileType = '只能上传图片类型格式';  }  // if ($strInfo['chars1']=='-1' AND $strInfo['chars2']=='-40' ) return 'jpg';  // if ($strInfo['chars1']=='-119' AND $strInfo['chars2']=='80' ) return 'png';  return $fileType; }