Read tags from a binary stream

tag-read.c

#include <stdio.h>
#include <stdint.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

int main(int argc, char **argv) {
        int f = open("args.bin", O_RDONLY);
        uint8_t fourcc[4];
        uint32_t val;
        uint32_t size;
        int i;

        while (1) {
                int res;

                res = read(f, &fourcc, 4);
                if (res != 4)
                        break;
                res = read(f, &size, 4);
                if (res != 4) {
                        fprintf(stderr, "Trailing data\n");
                        break;
                }

                fprintf(stderr, "%c%c%c%c (%d bytes):", fourcc[0], fourcc[1], fourcc[2], fourcc[3], size);

                for (i = 0; i < size; i += 4) {
                        res = read(f, &val, 4);
                        if (res != 4) {
                                fprintf(stderr, "Short read!\n");
                                break;
                        }
                        fprintf(stderr, " %08x", val);
                }
                fprintf(stderr, "\n");
        }
        fprintf(stderr, "\n");


        return 0;
}