How to create increment folder name in php - php

Question

I have an HTML form with three inputs:
name
consultant id (number)
picture upload
After the user submits the form, a php script would:
Create folder with the submitted name
Inside the folder create a txt file with: name + consultant id (given number)
Inside the folder, store the image uploaded by user
The most important thing I want is that folders created by the php file should be increased by 1. What I mean: folder1 (txt file + image), folder2 (txt file + image), folder3 (txtfile + image) and so on...

Answer 1

There are a few different methods for accomplishing what you describe. One option would be look at all existing folders(directories) when you attempt to create a new one and determine the next highest number.
You can accomplish this by using scandir on your parent output directory to find existing files.
Example:
$max=0;
$files=scandir("/path/to/your/output-directory");
$matches=[];
foreach($files as $file){
if(preg_match("/folder(\d+)/", $file, $matches){
$number=intval($matches[1]);
if($number>$max)
$max=$number;
}
}
$newNumber=$max+1;
That is a simple example to get you the next number. There are many other factors to consider. For instance, what happens if two users submit the form concurrently? You would need some synchronization metaphor(such as semaphore or file lock) to ensure only insert can occur at a time.
You could use a separate lock file to store the current number and function as a synchronization method.
I would highly encourage finding a different way to store the data. Using a database to store this data may be a better option.
If you need to store the files on disk, locally, you may consider other options for generating the directory name. You could use a timestamp, a hash of the data, or a combination thereof, for instance. You may also be able to get by with something like uniqid. Any filesystem option will require some form of synchronization to address race conditions.
Here is a more complete example for sequentially creating directories using a lock file for the sequence and synchronization. This omits some error handling that should be added for production code, but should provide the core functionality.
define("LOCK_FILE", "/some/file/path"); //A file for synchronization and to store the counter
define("OUTPUT_DIRECTORY", "/some/directory"); //The directory where you want to write your folders
//Open the lock file
$file=fopen(LOCK_FILE, "r+");
if(flock($file, LOCK_EX)){
//Read the current value of the file, if empty, default to 0
$last=fgets($file);
if(empty($last))
$last=0;
//Increment to get the current ID
$current=$last+1;
//Write over the existing value(a larger number will always completely overwrite a smaller number written from the same position)
rewind($file);
fwrite($file, (string)$current);
fflush($file);
//Determine the path for the next directory
$dir=OUTPUT_DIRECTORY."/folder$current";
if(file_exists($dir))
die("Directory $dir already exists. Lock may have been reset");
//Create the next directory
mkdir($dir);
//TODO: Write your content to $dir (You'll need to provide this piece)
//Release the lock
flock($file, LOCK_UN);
}
else{
die("Unable to acquire lock");
}
//Always close the file handle
fclose($file);