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.

See my updated version of this script called A Better PHP Upload and Rename Script.

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”.

Husnain said on 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

Zac said on May 5, 2009