Log analysis with map

In this recipe, we will use map to analyze the access log for the Apache web server. The log contains access parameters for each host accessing the web server per line. The log looks like this:

    64.242.88.10 - - [07/Mar/2004:16:10:02 -0800] "GET
     /mailman/listinfo/hsdivision HTTP/1.1" 200 6291
    64.242.88.10 - - [07/Mar/2004:16:11:58 -0800] "GET 
     /twiki/bin/view/TWiki/WikiSyntax HTTP/1.1" 200 7352
    64.242.88.10 - - [07/Mar/2004:16:20:55 -0800] "GET 
     /twiki/bin/view/Main/DCCAndPostFix HTTP/1.1" 200 
     5253

The line starts with hostname or IP that is accessing the web server. The remaining part of the line includes date and time, method of access (GET, PUT, POST, and so on), and the path of the web server being accessed. The server also prints status information.

How to do it...

1. Create a new project log-parser with the simple Stack template:

        stack new log-parser simple

2. Open log-parser.cabal and add the library containers as a dependent library...