Unlinking files when session over?

the_lar

Hi,

I'm developing a mapping tool which allows the user to upload the map as an image.

I don't want to end up with hundreds of image files gobbling up my webspace though so I need some way of automatically removing them when the user has finished. My theory is to start a session when the user uploads the map and make the filename the session_id() thus making it unique. I would like to automatically unlink the file when the user closes the window. Would this be possible or am I going to have to write a separate script that checks against live sessions?

All ideas welcome, thanks in advance.

Lar

drew010

instead of doing that, you should save the images as the timestamp of when they are uploaded. that way you can have cron run a script to just go thru and delete all images that are older than x days or hours, since there is no absolute way to have files deleted when a session ends or when a user closes the browser. you could use a javascript onUnload event to pop a new window to a script to delete it, but some users will have popup blockers or close it before it loads.

so you will have images like 1085779870.jpg and the cron will list all the files in a dir and just look at the timestamp part by exploding out the . and calculate the age and delete if necessary. hopefully you understood all that 😉

the_lar

Yes, totally got that - I know it's only a really small chance but what if two users upload at the same time. I suppose I could just tag on the first 4 digits of a session_id() to ensure uniqueness.

Lar

drew010

it will be accurate to the second so unless there are lots of people on at the saem time uploading, chances of that are rare. if you want you can tack on the microseconds too using microtime.

BuzzLY

um... I could be missing something here, but couldn't you just have the cron job delete files according to their timestamps? Then you don't have to worry about file naming issues. Use the session id to name the file if you want. Seems a little redundant to use date/time to name the file, if the file already has a timestamp...

If I am wrong in my assumptions, please let me know how. I am certainly not a *nix expert, and don't know much about cron jobs.