No file while renaming in PHP?

Question

Thanks to a cron PHP process, some temporary files are created and then renamed (with rename() ) so as to replace files that users access.

Is it possible that a user requests a page while it's being replaced by renaming, and there is no file ? Is there such an "in-between time" (even very small) ?

Answer 1

If you were deleting the old file and moving a new one into it's place, it is certainly possible that some users will try to access a file that does not exist. If you are renaming it without deleting the old file (overwriting), you will not run into any issues if you're on Linux . You are out of luck if you're on windows though .

You would need to write your own locking procedure in the latter case, using flock() for example.