Bitwise (need help not answer)
I'm studying bit manipulation. My assignment is to write two functions. 1. convert string to all upper, 2. convert string to all lower. The trick is that I cannot use toupper or tolower. I have to use bit manipulation. I have read many articles and the chapters of various books on bitwise. It's very hard to find real world examples showing bit manipulation in C. Or at least I just don't know how to look for them.
What I know (or think I know)...
I understand that the easiest way to manipulate bits in C is to use hex. I have read and understand the basics of binary and hexadecimal. I understand that the difference between an uppercase character and a lowercase character is the 3rd lower order bit (I think). I understand how to create a mask to turn on and off this bit. But I just don't get how to get a char (getchar?), and manipulate a specific bit of that character using the mask.
Can anyone suggest a tutorial or provide any insight?