recover.c ver.2

/**
 * recover.c
 *
 * Computer Science 50
 * Problem Set 4
 *
 * Recovers JPEGs from a forensic image.
 */
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

typedef uint8_t  BYTE;

int main(void)
{
    // open CF card
    FILE* inptr = fopen("card.raw", "r");
    if (inptr == NULL)
    {
        printf("Could not open \n");
        return 1;
    }



    int j = 0;     // counter for jpeg file
    char title[8];  // file name for jpeg file
    BYTE block[512]; // 512byte chunk of memory
    int f = 0;       // state jpg not found
    FILE* outptr = NULL;

    while(!feof(inptr))
    {
        fread(block, sizeof(block), 1, inptr); // read 512byte from cf card

        if(block[0] == 0xff && block[1] == 0xd8 && block[2] == 0xff && (block[3] >= 0xe0 && block[3] <= 0xef))
        {
            if(outptr != NULL)
                fclose(outptr);

            f = 1;   // jpeg found
            sprintf(title, "%03d.jpg", j);
            j++;

            outptr = fopen(title,"a");
        }
        if(f == 1)
            fwrite(block, sizeof(block), 1, outptr);
    }
    fclose(inptr);
    fclose(outptr);
    return 0;
}