1.31字节PHP随机显示头像
<?readfile(rand(0,5).'.jpg');?>



2.
<?php

$url='pic';
//图片地址，用相对路径

$files=array();
if($handle=opendir("$url")){
while(false!==($file=readdir($handle))){
if($file!="."&&$file!=".."){
if(substr($file,-3)=='gif'
substr($file,-3)=='jpg')$files[count($files)]=$file;
}
}
}
closedir($handle);

$random=rand(0,count($files)-1);
if(substr($files[$random],-3)=='gif')header("Content-type:image/gif");
elseif(substr($files[$random],-3)=='jpg')header("Content-type:image/jpeg");
readfile("$url/$files[$random]");

?>