79. Extract Packet Fields from Byte Stream

#include <stdio.h>
#include <stdint.h>

typedef struct {
    uint8_t start;
    uint8_t command;
    uint16_t data;
    uint8_t crc;
    uint8_t end;
} Packet;

typedef union {
    Packet pkt;
    uint8_t arr[6];
}packet_un;

void print_packet_fields(uint8_t *buffer) {
    // Overlay struct and print values
    packet_un p;
    p.arr[0] = *buffer;
    p.arr[1] = *(buffer+1);
    p.arr[2] = *(buffer+2);
    p.arr[3] = *(buffer+3);
    p.arr[4] = *(buffer+4);
    p.arr[5] = *(buffer+5);

    printf("Start: %u\n",p.pkt.start);
    printf("Command: %u\n",p.pkt.command);
    printf("Data: %u\n",p.pkt.data);
    printf("CRC: %u\n",p.pkt.crc);
    printf("End: %u\n",p.pkt.end);
}

int main() {
    uint8_t buffer[6];
    for (int i = 0; i < 6; i++) {
        scanf("%hhu", &buffer[i]);
    }
    print_packet_fields(buffer);
    return 0;
}