Replace save files if from same User - php

Question

I have a directory called resale_certificates where I save files to but encrypt the name using parts of their email and codes assigned to them.
NOTE: The encryption is the same every time but unique to each user!
When they upload image.png it will save the file to theirEncrypt.png
If they upload another image.png it will replace theirEncrypt.png
However when they upload image.jpg now there will be theirEncrypt.jpg and theirEncrypt.png in the resale_certificates directory.
What is the best way to handle this? I'm looking for advice and open to changing how I'm saving it or tricks I could do to prevent this!
Thank You!

Answer 1

Well, you could use an image library to transform their uploaded image to whatever format you want, i.e. if they upload a .JPG you can use image libraries like Imagick or GD to output a .PNG file and upload those.
However, if you don't mind either the .JPG or .PNG ( or .GIF for that matter) you can scan the directory with PHP to look for all files ( can be really intensive though! ) to look for files with the name given.
For example:
<?php
foreach( scandir('/path/to/resale_certificates/') as $file ){
if( $file != '.' && $file != '..'){
// explode so we remove the last extension path ( not type safe ! )
$arguments = explode('.', $file);
// store the last part
$ext = end($arguments);
// pop the extension from the $arguments array so we are left
// with whatever was left
array_pop($arguments);
// concatenate the $arguments into a single string again
$filename = implode('.', $arguments);
// now we can check the filename again
if( $filename == $theirEncrypt){
unlink('/path/to/resale_certificates/' . $filename . '.' . $ext);
}
}
}
edit:
the $file is a string from the $files array returned by the scandir(); function. The single and double dot are a ways to navigate to the current (.) and the parent (..) directory and are therefore symlinks. Another option would be to check if the $file is actually a file. You could replace the comparison line with a is_file('/path/to/resale_certificates/' . $file) to check if it's a file or a symlink ( like the . and the .. ) but it's even more intensive then to check string comparison. In your usecase it is not neccesary.
On a related note, this is quite intensive, depending on the number of clients and certificates you have, you could, as an alternative, store the filename to storage (i.e. database or something similiar) and just unlink the file find there, this would save you to iterate over each file and simply unlink the file directly.

Answer 2

If you know a name of previously uploaded image then you can do the following before saving a new image:
<?php
$previousImageName = 'theirEncrypt.png';
unlink(APP_DIR . "/resale_certificates/" . $previousImageName);