You want to count the number of times a page has been accessed. This can be used to display a hit counter in the page. The same technique can be used to record other types of information as well, such as the number of times each of a set of banner ads has been served.
Implement a hit counter, keyed to the page you want to count.
This section discusses access counting, using hit counters for the examples. Counters that display the number of times a web page has been accessed are not such a big thing as they used to be, presumably because page authors now realize that most visitors don’t really care how popular a page is. Still, the general concept has application in several contexts. For example, if you’re displaying banner ads in your pages (Recipe 17.8), you may be charging vendors by the number of times you serve their ads. To do so, you need to count the number of accesses for each one. You can adapt the technique shown in this section for purposes such as these.
There are several methods for writing a page that displays a count of the number of times it has been accessed. The most basic is to maintain the count in a file. When the page is requested, you open the file, read the count, increment it and write the new count back to the file and display it in the page. This has the advantage of being easy to implement and the disadvantage that it requires a counter file for each page that includes a hit count. It also doesn’t work ...