Program code to restrict uploaded file types_PHP tutorial

<script><br>function check(){<br>var filepath=path.value<br>filepath=filepath.substring(filepath.lastIndexOf('.')+1,filepath.length)<br>if(filepath != 'jpg' && filepath != 'gif')<br>alert("只能上传JPG或GIF格式的图片")<br>}<br></script>

(只能上传JPG或GIF格式的图片)

<script><br>function ck(obj){if(obj.value.length>0){<br>var af="jpg,gif,png,zip,rar,txt,htm";<br>if(eval("with(obj.value)if(!/"+af.split(",").join("|")+"/ig.test(substring(lastIndexOf('.')</p> <p>+1,length)))1;")){alert("Allowed file types:n"+af);obj.createTextRange().execCommand('delete')};<br>}}<br></script>

/*
 * 判断图片类型
 *
 * @param ths
 *    type="file"的javascript对象
 * @return true-符合要求,false-不符合
 */
function checkImgType(ths){
 if (ths.value == "") {
  alert("请上传图片");
  return false;
 } else {
  if (!/.(gif|jpg|jpeg|png|GIF|JPG|PNG)$/.test(ths.value)) {
   alert("图片类型必须是.gif,jpeg,jpg,png中的一种");
   ths.value = "";
   return false;
  }
 }
 return true;
}

$name=$_FILES['file4']['name']; //获取客户端机器原文件的名称
$type=strstr($name,"."); //获取从"."到最后的字符 if($type!=".txt")
{ echo "对不起,您上传文件的格式不正确!!";
echo "将在3秒钟后返回前页...";
}