Skimmed through the article and found a small mistake. That means that (*argv)[0] is the first character of the program name and (*argv)[1] is the first char

Skimmed through the article and found a small mistake. That means that (*argv)[0] is the first character of the program name and (*argv)[1] is the first character of the first argument. (*argv)[1] is the second character of the program name (in this case), not first character of first argument.