Autorename extracted files from zip-archive

Hello, I am using shell_exec to uncompress zip files which works fine, but has one big problem. Whenever the zip-archive containes an already existing file name, it will overwrite the current one. I need the file to be extracted and autorenamed. This is the code line: $output = shell_exec('unzip -jo '.$filename.' -d '.$path); Does anybody know a way on how to autorename existing files? I thought about a workaround on extracting to a tmp folder and then moving to the proper directory while renaming the files if they already exists. Unfortunatelly I could not find a way to do this. Thank you for any help on this. Merlin