How to increment filename in php to prevent duplicates

Question

In many situations, we need to make the filename different on the server when creating them to prevent duplication. And the most common answer to that seems to be, append the timestamp at the end or store the filename in the db and use those stored values to compute new name. These are good and all, but, appending a long time-stamp isn't always very user-friendly, and storing in the db isn't always an option. So, how can we auto-increment a standard filename while creating it via php?

Answer 1

All these answers seem overkill:

$k = 0;
while(!$result){
    if(!file_exists("file[$k].ext"))
        $result = "file[$k].ext";
    $k++;
}
makefile($result);

Answer 2

Here's a simple function I wrote for this purpose:

function incrementFileName($file_path,$filename){
 if(count(glob($file_path.$filename))>0)
 {
     $file_ext = end(explode(".", $filename));
     $file_name = str_replace(('.'.$file_ext),"",$filename);
     $newfilename = $file_name.'_'.count(glob($file_path."$file_name*.$file_ext")).'.'.$file_ext;
     return $newfilename;
  }
  else
  {
     return $filename;
  }
}

USAGE:

$newName = incrementFileName( "uploads/", $_FILES["my_file"]["name"] );
move_uploaded_file($_FILES["my_file"]["tmp_name"],"uploads/".$newName);

Answer 3

Here is a short code snippet that demonstrates how you might start solving this problem.

// handle filename collision:
if(file_exists($newFile)) {
    // store extension and file name
    $extension = pathinfo($newFile,PATHINFO_EXTENSION);
    $filename = pathinfo($newFile, PATHINFO_FILENAME);

    // Start at dup 1, and keep iterating until we find open dup number
    $duplicateCounter = 1;
    // build a possible file name and see if it is available
    while(file_exists($iterativeFileName =
                        $newPath ."/". $filename ."_". $duplicateCounter .".". $extension)) {
        $duplicateCounter++;
    }

    $newFile = $iterativeFileName;
}

// If we get here, either we've avoided the if statement altogether, and no new name is necessary..
// Or we have landed on a new file name that is available for our use.
// In either case, it is now safe to create a file with the name $newFile