<?php
//创立文件夹
function mk_dir($dir, $mode = 0700){
 //假如上传路径没有"/"，加上"/"
  if (!preg_match("/(.+)\/$/",$dir)) {
  $dir .= "/";
 }
 
 //循环建立文件夹
 if (!file_exists($dir)){
  $dirArray=explode("/",$dir);
  foreach($dirArray as $v){
   $newpath .= $v."/";
   mk_dir(dirname($newpath));
   @mkdir($dir, 0777);
  }
 }  
}

//检测文件类型 
function checkmime($filename) {
 //JPG,GIF,BMP,PNG
 $File = fopen($filename, "rb");
 $bin = fread($File, 2); //只读2字节 
 fclose($File);
 $strInfo = @unpack("C2chars", $bin); 
 $typeCode = intval($strInfo['chars1'].$strInfo['chars2']); 
 $FileType = array("255216","7173","6677","13780");
 if(in_array($typeCode,$FileType)) {
  return TRUE;
 }
}

//上传文件
function upload($file,$dir){
 //创立文件夹
 mk_dir($dir,0755);

 // 判断文件按大小
 if($_FILES["$file"][size]>500000) {
  echo "<script>";
  echo "alert('上传文件超过规定大小范围!');";
  echo "location.href='javascript:history.go(-1)';";
  echo "</script>";
 }
 
 //判断文件格式。
 $fileType = array("image/jpeg","image/bmp","image/gif","image/pjpeg");
 if(!in_array($_FILES["$file"][type],$fileType)) {
  echo "<script>";
  echo "alert('不支持此类文件上传!');";
  echo "location.href='javascript:history.go(-1)';";
  echo "</script>";
 }
 

 //上传文件，返回上传文件的路径和名称
 if ($_FILES["$file"][error]) {
  echo "<script>";
  echo "alert('上传文件失败!');";
  echo "location.href='javascript:history.go(-1)';";
  echo "</script>";
 } else {
       //假如文件上传成功
       if (move_uploaded_file($_FILES["$file"][tmp_name],$dir.$_FILES["$file"][name])) {  
        //判断文件格式。
    if(!checkmime($dir.$_FILES["$file"][name])){
    @unlink ($dir.$_FILES["$file"][name]);
    echo "<script>";
    echo "alert('此文件类型可疑，已删除!');";
    echo "location.href='javascript:history.go(-1)';";
    echo "</script>";
   } else {
    return $dir.$_FILES["$file"][name]; 
   }

       }
 }
}

-------------------------------------------------------------------------------------------------------------------------------------------------

//创立文件夹
function mk_dir($dir, $mode = 0700){
 //假如上传路径没有"/"，加上"/"
  if (!preg_match("/(.+)\/$/",$dir)) {
  $dir .= "/";
 }
 
 //循环建立文件夹
 if (!file_exists($dir)){
  $dirArray=explode("/",$dir);
  foreach($dirArray as $v){
   $newpath .= $v."/";
   mk_dir(dirname($newpath));
   @mkdir($dir, 0777);
  }
 }  
}

//检测文件类型 
function checkmime($filename) {
 //JPG,GIF,BMP,PNG
 $File = fopen($filename, "rb");
 $bin = fread($File, 2); //只读2字节 
 fclose($File);
 $strInfo = @unpack("C2chars", $bin); 
 $typeCode = intval($strInfo['chars1'].$strInfo['chars2']); 
 $FileType = array("255216","7173","6677","13780");
 if(in_array($typeCode,$FileType)) {
  return TRUE;
 }
}
?>