Upload and Rename a File with PHP

Eventually every programmer will be required to find a way to upload a file to a web server. I recently started a project that required a way for me to upload a word doc to a web server, which, in turn, required me to write a upload and rename script in PHP.

So, here are the steps I went through to get a word doc to upload to a directory on my web server.

Step 1: Build the Form

I am just going to assume you know how to build an upload form in HTML. But just in case, here is the code I used:

<form action="<?php echo $_SERVER['PHP_SELF'];?>" method="post" enctype="multipart/form-data" name="file_upload">
	<input type="file" name="file" id="file">
	<input type="hidden" name="execute" id="execute">
	<input type="submit" name="Submit" id="Submit" value="Submit">
</form>

This form, of course, lets me post a file to a temp directory on the web server. Once our file is posted, we then validate the file type, size, and if everything checks out, move the file to its final destination.

Step 2: The Code

Here is the code that puts out file on the server, checks the file type, and does some error reporting.

<?php
// Upload and Rename File
if (isset($_POST['execute'])) {
 
$filename = $_FILES["file"]["name"];
$file_basename = substr($filename, 0, strripos($filename, '.')); // strip extention
$file_ext = substr($filename, strripos($filename, '.')); // strip name
$filesize = $_FILES["file"]["size"];
 
	if (($file_ext == ".doc" || $file_ext == ".docx")  &&  ($filesize < 200000)) {
		// rename file
		$newfilename = md5($file_basename) . $file_ext;
 
		if (file_exists("upload/" . $newfilename)) {
			// file already exists error
			$error = "You have already submitted this file.";
		} else {
			move_uploaded_file($_FILES["file"]["tmp_name"], "upload/" . $newfilename);
			echo "File uploaded successfully.";
		}
	} elseif (empty($file_basename)) {
		// file type error
		$error = "Please select a file to upload.";
	} else {
		// file selection error
		$error = "Only doc, docx, rtf, pdf, and txt files can be submitted online.";
		unlink($_FILES["file"]["tmp_name"]);
	}
}
?>

Everything is this code is commented pretty well. The important lines of code here are where the new file name is built ($newfilename) and where the file, if valid, is moved to its final location (move_uploaded_file()). Make sure you set the final file directory in the move_uploaded_file() command. Otherwise, the script will fail.

Added Bonus: This Script Can Upload Anything

Just so you know, you can upload anything to a web server with this script. All you need to do is change the allowed extensions near $file_ext == “.doc”.

Comments

1. Husnain(May 5, 2009)

   Hi,
   It works fine, but this code has a problem, when a file is uploaded twice with same name it does not work. Please inform where to change code.
   Thanks
2. Zac(May 5, 2009)

   Hi Husnain,

   You should have no problems changing the code to work with the same file over and over. Try changing this line:

   $newfilename = md5($file_basename) . $file_ext;

   to something like

   $newfilename = md5(time() . $file_basename) . $file_ext;

   Let me know if that works for you.
3. Saguenay(May 23, 2009)

   Great tutorial! Thanks!
4. YooNet(June 25, 2009)

   Hi,

   Nice script, how do i show the url to the file?

   Many Thanks!
5. Zac(June 25, 2009)

   Hi YooNet,

   Try adding this to line 20–it should give you a path to the file:

   echo “upload/” . $newfilename;
6. aleks(August 8, 2009)

   very well said! thanks for this…it really helps me a lot

   kind regards,
   ~aleks
7. SHW(September 11, 2009)

   Thanks, man. This was exactly what I was looking for!
   You helped me a lot. I just wanted to let you know
   Greetings from Germany
8. Asanka lakmal(October 28, 2009)

   Great work. Thanks very much

   Asanka
9. Juussi(February 2, 2010)

   Hello. Thanks for this.

   Is it possible to ‘post’ also a wanted new file name and rename the sent file in server site?