Read and write to a file while keeping lock

Question

I am making a simple page load counter by storing the current count in a file. This is how I want to do this:

1. Lock the file (flock)
2. Read the current c

Answer 1

I believe you can achieve this using flock. Open a pointer to your file, flock it, read the data, write the data, then close (close automatically unlocks).

http://php.net/flock