Solved Can portable software use the %TEMP% folder?

Need an opinion... we're working on a product that uses a lot of temporary data files, but want our app to be portable, because our mantra is that our apps don't modify files outside their own folder.

However, it seems to make sense that we store this temp data in the %TEMP% folder of the current user. Does that make our app non-portable? Would it be misleading to advertise it as portable in this case? Or is %TEMP% an exception?

Thanks for your thoughts.

 

A question I would ask is: does your app clean up these temp files?

If it needs them in a subsequent launch then there is no guarantee that the temp files will not have been cleaned by the user or by a tool used to clean the drive.

 

The files are not kept. When the app launches, it deletes any existing ones first, then does its business. On closing, it also deletes them.

But I'm more worried that this means the app isn't portable in the true sense? Say if the user has it on a USB stick and runs it in a public library, the files won't be stored on his stick, but rather in the host PC's %TEMP% folder. That may be a privacy issue?

 

If your app creates files that have personal info in them then I'd create them in the home folder, using a folder for it.

The %temp% folder is a free-for-all and any app can write files and folders there though,
so IMO a portable app can use it as legitimately as a statically installed app.

 

Thanks for your thoughts. I've decided it's best that we put the temporary files into the user's own personal folder (CSIDL_PERSONAL, aka "My Documents"). A lot of other apps seem to do that, so it should be fine.

 

Is this the "My Documents" user folder of the logged in user at the Library?
That folder is no better than the %temp% folder - in fact it's worse because it's public and in plain view.

Some libraries use "Deep Freeze" or similar to restore the OS to a default state between users, but not all do.

 

I'll agree with Foxdrive, feeling it would be intrusive to use My Documents. I hate the folder (try not to use it) but when I go there I expect to see stuff I put there not stuff from an App. I might delete them not sure what they where. The way you describe you app I think Temp would be fine.

 

But if I use %Temp%, what's to stop an app like CCleaner wiping out the files while they're in use?

 

Only by people realising that CCleaner removes unlocked temp files of open programs too.

You could create a brand new folder in "%userprofile%" which is the logged in users home folder, and a folder in that place can be a name that you choose, and it is persistent too in a regular users PC.

It does seem to me though that a portable app should be using the folder where the app is, even if it's a new folder inside it.

Portable apps like the modified Thunderbird store everything in the same place AFAIK.

 

You're right... we'll go instead with the local folder where the exe is, after all. Probably best all-round. Thanks for the discussion and points of view!