#include <stdio.h>
#include <stdlib.h>

// tests
// ./contains_byte_stdio examples/empty.txt 0x61
// ./contains_byte_stdio examples/lorem.txt 0x61
// ./contains_byte_stdio f 0xff
// ./contains_byte_stdio f 0x0

int contains_byte(char *path, unsigned char byte);

int main(int argc, char *argv[]) {
    if (argc <= 2) {
        fprintf(stderr, "Usage: %s <filename> <byte>\n", argv[0]);
        return 1;
    }
    unsigned char byte = strtoul(argv[2], NULL, 0);
    if (contains_byte(argv[1],byte)){
        printf("Contains byte 0x%x\n", byte);
    } else {
        printf("Does not contain byte 0x%x\n", byte);
    }

    return 0;
}

// Return 1 of the  given file contains the given byte.
// Return 0 otherwise
int contains_byte(char *path, unsigned char byte) {
    FILE *f = fopen(path, "r");
    if (f == NULL) {
        perror("");
        exit(1);
    }

    //read each byte and compare
    int curr_byte;
    while ((curr_byte = fgetc(f)) != EOF){
        if (curr_byte == byte) {
            fclose(f);
            return 1;
        }
    }

    fclose(f);
    return 0;
}