Read/Write conflict?

[high6]

I was wondering if it was possible to have a conflict reading and writing to a file if 2 people were to request the php file at the same time.

[visualAd]

Not with reading and writing because the newer version of the file will only be available when it has been written. There is a possibility that two process can open the a file for writing at the same time and cause update to be made in the wrong order. You should create a lock file to signify the file is open for writing.