It's a wonderful problem for optimizing code. Michael Abrash hosted a performance contest for word counting back in... 1991? (If my memory serves.) The article and code can be found here:

There Ain’t No Such Thing as the Fastest Code: Lessons Learned in the Pursuit of the Ultimate Word Counter

Article: https://www.phatcode.net/res/224/files/html/ch16/16-01.html

Code: https://www.phatcode.net/res/224/files/html/ch16/16-05.html