hexdump.c

#include <stdio.h>
#include <string.h>

char raw[] = "\x0d\x0a\x00\x11\x22\x33\x44\x55\x66\x77\x88\x99\xaa\xbb\xcc\xdd\xee\xff";


void hexdump(char *ptr, int len, int width) {
    int count = 1;
    printf("--------------------\n");
    for(;len>0;len--,ptr++,count++) {
        printf("%02X", (unsigned char)ptr[0]);
        if (count==width) {
            count = 0;
            printf("\n");
        } else {
            printf(" ");
        }  
    }
    printf("\n");
    printf("--------------------\n");
}

int main() {
    hexdump(raw, sizeof(raw), 8);
}

--------------------
0D 0A 00 11 22 33 44 55
66 77 88 99 AA BB CC DD
EE FF 00 
--------------------