I once made a somewhat similar error. Many years ago, when I was just learning PHP, I attempted to write a function to delete all the contents of a directory, i

I once made a somewhat similar error. Many years ago, when I was just learning PHP, I attempted to write a function to delete all the contents of a directory, including subdirectories. I don't remember the exact code, but it was something like: function clear_dir($dir) { $contents = scandir($dir); // returns array of directory contents foreach($dir => $file) { if(is_dir($file)) { clear_dir($file); } else { unlink($file); } } } The function names may not all be correct, been a while since I PHP'd Anyway, so the code looks like it should work. The problem is the scandir function result includes . and .. So my little function would see .., recognise it as a directory, and recursively call itself on the parent of the directory I wanted to empty. I lost a fair few files before I realised what was happening. Luckily I had back ups, as this was before I started using SCMs.