How to understand when the picture was last opened by the link?

Question

PHP

images.vfl.ru/ii/1519229096/9b49a31d/20677904.jpg
There is a link
How to understand when the last time a picture was opened via a link, I have a hosting of pictures I want to delete a picture from the hosting if it has not been opened for a long time?

Answer 1

give images indirectly and keep logs if you are not aware of the web server logs.

Answer 2

If the filesystem has not been 'tuned' by disabling the noatime option in linux (in windows there is an analogue of the option somewhere in the registry for ntfs), then the files will be correctly set to the date the file was last accessed.
https://secure.php.net/manual/ru/function.fileatime.php