rec

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

// Prolly should be in a header file
typedef uint8_t BYTE;
// Size of blocks in FAT
typedef struct
{
    BYTE bytes[512];
} BLOCK_SIZE;

bool check_block(BLOCK_SIZE *block);

int main(int argc, char *argv[])
{
    if (argc != 2)
    {
        printf("Invalid argument");
        return 1;
    }
    FILE *file = fopen(argv[1], "r");
    if (file == NULL)
    {
        printf("Cannot open file");
        return 2;
    }
    FILE *out;
    char *fname = malloc(8 * sizeof(char));

    bool if_open = false;
    int files = 0;
    BLOCK_SIZE *block = calloc(1, sizeof(BLOCK_SIZE));
    while (fread(block, sizeof(BLOCK_SIZE), 1, file))
    {
        //Prolly do while loop fits better for writing
        if (check_block(block)) // Check first 4 Bs in a block
        {
            if_open = true;
            sprintf(fname, "%.3d.jpg", files);
            out = fopen(fname, "w");
            if (out == NULL)
            {
                printf("Cannot create file\n");
                fclose(out);
                fclose(file);
                return 3;
            }
            files++;
        }
        if (if_open)
        {
            fwrite(block, sizeof(BLOCK_SIZE), 1, out);
        }
    }
    fclose(file);
    fclose(out);
    free(fname);
}

bool check_block(BLOCK_SIZE *block)
{
    /* //Probably better with 4 explicit if statements
    short first_Bs_flags = 0;
    for (int i = 0; i < 4; i++) //Check only for 4 first Bytes of a block
    {
        if (block->bytes[i] == 0xff || block->bytes[i] == 0xd8)
        {
            first_Bs_flags++;
        }
        else if (i == 3)
        {
            for (int j = 0; j < 16; j++)
            {
                if (block->bytes[i] == 0xe0 + j)
                {
                    first_Bs_flags++;
                    break;
                }
            }
        }
    } */
    short first_Bs_flags = 0;
    if (block->bytes[0] == 0xff && block->bytes[1] == 0xd8 && block->bytes[2] == 0xff)
    {
        first_Bs_flags += 3;
    }
    for (int j = 0; j < 16; j++)
    {
        if (block->bytes[3] == 0xe0 + j)
        {
            first_Bs_flags++;
            break;
        }
    }
    return first_Bs_flags == 4 ? true : false;
}