从用户代理字符串确定哪个浏览器发出了请求

I am trying to write a batch file for reading and extracting user agent from a log file which i am able to do with the following code but i need to give numeric count of the browser that made the requests and Using gnu-plot, plot a bar-chart of the number of requests per browser.i am kinda stuck with the browser requests a little help or direction will be appreciated.I am trying to write a batch file for reading a