Question

is there any way that I can capitalize argv, such as argv[1] = hello, and argv[2] = world to argv[1] = HELLO, argv[2] = WORLD without using strlen or toupper or copy them into new arry?

Answer 1

#include <stdio.h>

int main(int argc, char *argv[]) {
    if (argc > 1) {
        int i, j;
        for (i = 1; i < argc; ++i) {
            j = 0;
            while (argv[i][j]) {
                if (argv[i][j] >= 'a' && argv[i][j] <= 'z')
                    argv[i][j] -= 32;   // to change lowercase letter to uppercase letter subtract 32 from letter
                j++;
            }
            printf("%s\n", argv[i]);
        }
    }
    return 0;
}

// directly modified argv into uppercase (no libraries used)