recover.c

/**
 * recover.c
 *
 * Computer Science 50
 * Problem Set 4
 *
 * Recovers JPEGs from a forensic image.
 */
 
#include <stdio.h>
#include <cs50.h>
#include <stdint.h>
 
#define BLOCKSIZE 512 
#define BYTE 8


int main(void)
{
    FILE* memory = fopen("card.raw", "r");
    if (memory == NULL)
    {
        printf("Couldn't open memory card\n");
        return 1;
    }
    
    uint8_t buffer[BLOCKSIZE];
    int counter = 0;
    FILE* images = NULL;
    
    while(fread(buffer, BLOCKSIZE, 1, memory) == 1)
    {
      
    
        if(((buffer[0] = 0xff) && (buffer[1] == 0xd8) && (buffer[2] == 0xff)) &&
        ((buffer[3] == 0xe0) || (buffer[3] == 0xe1)))
        {
            if (images != NULL)
            {
                fclose(images);
            }
            char recovered[BYTE];
            sprintf(recovered, "%03d.jpg", counter);
            images = fopen(recovered, "w");
            counter++;
        }
        if (images != NULL)
        {
            fwrite(buffer, BLOCKSIZE, 1, images);
        }
        
    }
    if (images != NULL)
    {
        fclose(images);
    }
    fclose(memory);
    
    return 0;
}