How to add a check for the absence of spaces in C?

Question

C++ / C#

Hello, I have a code that takes a serial input of characters as input and converts the characters to hexadecimal. ignoring spaces.

#include <stdio.h>

int decod (void);

int main() {
    decod();
}


int decod (void) {
    int s;
    while ((s = getchar()) != '\n') {
        if (s != ' ') {
            printf("%X ", s);
        }
    }
}
}

the code accepts WORLD as input and gives 57 4F 52 4C 44 as output
How to make a check that the program gives an error message at the WORLD input? (you cannot enter characters without spaces)
Thanks in advance

Answer 1

Set the error flag before checking. At the first space (more precisely, at each) reset the flag.