PHP code to change the suffix extension of all files in a directory and subdirectories

I don't deal with files very often, so I'm not very familiar with directory traversal. I searched for information and modified it myself.
Let everyone see if it needs to be improved
The main purpose of the code is to change the file suffix in batches. Since the Taobao data package image types are different, it needs to be changed appropriately.

Copy the code The code is as follows:

//This file and the file in the directory to be changed are placed in the same folder
define("STA",".gif"); //Original file format
define("END",".jpg"); //Format to be changed
$dir="./";
$arr=allfile($dir);
foreach($arr as $t)
{
$t=str_replace(".//","",$t);
if(substr_count($t,STA)>0)
{
$f2=str_replace(STA,"" ,$t);
rename($t,$f2.END);
}
}
//Function to get all files in the directory
function allfile($dir)
{
$files=array();
if (is_file($dir))
{
return $dir;
}
$handle = opendir($dir);
if($handle) {
while(false !== ($file = readdir($handle)) ) {
if ($file != '.' && $file != '..') {
$filename = $dir . "/" . $file;
if(is_file($filename)) {
$files [] = $filename;
}else {
$files = array_merge($files, allfile($filename));
}
}
} // end while
closedir($handle);
}
return $files;
}
?>

Replacing with string is not very strict. If there is a gif program in the name, there will be an exception.
It is recommended to use the PHP function pathinfo(). The loop section can be modified as

Copy the code The code is as follows:

foreach($arr as $t)
{
　$path_parts = pathinfo($t);
　if ($path_parts["extension"] == STA)
　{
　　rename($t,$path_parts["dirname"]."/".basename($t,STA).END);
　}
}

The above introduces the code for PHP to change the suffix extension of all files in the directory and subdirectories, including the content. I hope it will be helpful to friends who are interested in PHP tutorials.