How to use memcpy to set 2 hex byte data in char array

Question

I have a need to store the hex value from a character array x[11] to a memory space: char* content. The character array has contents like:

{'b', '5', 'a', '8', 'a', 'e', 'a', 'b', 'c', '7', '\n'}

And I need to save the ten elements except the \n. The following is how I did it:

char *content = (char *)calloc(msg_len, sizeof(char));
memcpy(content , x, 10);

The memory space output ended up to be in ASCII format:

62(b) 35(5) 61(a) 38(8) 61(a) ...

But what I hoped it to show in the memory is:

b5 a8 ae ab c7

Just like what it is in character array, shown above.

What steps can I take to to solve that?

Answer 1

Would something like this work?

#include <stdio.h>

int main() {
    char x[] = {'b', '5', 'a', '8', 'a', 'e', 'a', 'b', 'c', '7', '\n'};
    unsigned long long a;
    unsigned char b[5];
    sscanf(x, "%llx\n", &a);

    b[0] = a >> 32;
    b[1] = (a >> 24);
    b[2] = (a >> 16);
    b[3] = (a >> 8);
    b[4] = a ;

    for(int i = 0; i < 5; i++) {
        printf("%x ", b[i]);
    }
    printf("\n");
    return 0;
}