Lecture 8: Getting ready for program 1: unsigned chars and command line inputs

Key points:

To read command line input, define main with two input arguments: number of command line arguments and list of command line arguments, e.g. int main(int argc, char** argv) { }
Here argc is the number of command line argument sand argv is an array of character pointers containing all of the arguments.
To read one argument as an integer, use atoi(argv[1]). atoi is part of the standard library, so use #include <stdlib.h>

Key points:

char data type is actually one of many integer data types (see “Intege Types” here: https://www.tutorialspoint.com/cprogramming/c_data_types.htm)
unsigned char stores integers 0 to 255 using only 1 byte
use %hhu placeholder in strings for printf and scanf