Script php per rename in automatico e upload file

Ecco uno script utilissimo per caricare via form multipart/form-data un'immagine o qualsiasi file rinominandolo in automatico aggiungendo prima del nome del file 4 cifre random, cosi non dobbiamo preoccuparci se un esiste gia un immagine con lo stesso nome nella nostra directory.
Es del form per caricare

<form enctype="multipart/form-data" method="post" action="upload_rename.php">

<input type="file" name="ufile" >

<input type="submit">

</form>

Il file upload_rename.php a cui passare la variabile img

<?php

// Your file name you are uploading

$file_name = $HTTP_POST_FILES['ufile']['name'];

// random 4 digit to add to our file name

// some people use date and time in stead of random digit

$random_digit=rand(0000,9999);

//combine random digit to you file name to create new file name

//use dot (.) to combile these two variables

$new_file_name=$random_digit.$file_name;

//set where you want to store files

//in this example we keep file in folder upload

//$new_file_name = new upload file name

//for example upload file name cartoon.gif . $path will be upload/cartoon.gif

$path= "upload/".$new_file_name;

if($ufile !=none)

{

if(copy($HTTP_POST_FILES['ufile']['tmp_name'], $path))

{

echo "Successful<BR/>";

//$new_file_name = new file name

//$HTTP_POST_FILES['ufile']['size'] = file size

//$HTTP_POST_FILES['ufile']['type'] = type of file

echo "File Name :".$new_file_name."<BR/>";

echo "File Size :".$HTTP_POST_FILES['ufile']['size']."<BR/>";

echo "File Type :".$HTTP_POST_FILES['ufile']['type']."<BR/>";

}

else

{

echo "Error";

}

}

?>