RPI SPI echo program

#include <stdio.h>
#include <wiringPiSPI.h>

int main(void) {
        unsigned char data[100];
        unsigned char *ptr;
        ptr=data;
        wiringPiSPISetup (0, 16000000);
        while(1) {
                scanf("%s", data);
                wiringPiSPIDataRW (0, ptr, 100);
                printf("%s", *ptr);
        }
        return 0;
}