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

typedef struct
{
    uint8_t one;
    uint8_t two;
    uint8_t three;
    uint8_t four;
}header;

typedef struct
{
    char image[512];
}fat;

int main(int argc, char *argv[])
{
    // ensure proper usage
    if (argc != 2)
    {
        fprintf(stderr, "Usage: ./copy infile\n");
        return 1;
    }
    // remember filenames
    char *infile = argv[1];
    // open input file
    FILE *inp = fopen(infile, "r");
    if (inp == NULL)
    {
        fclose(inp);
        fprintf(stderr, "Doesnt exis %s.\n", infile);
        return 3;
    }
    header a = {0xff,0xd8,0xff,0xe0};
    uint8_t *b = malloc(sizeof(header));
    uint8_t byte=0;
    fat img;
    char title[100];
    int i=0,c = 1, jpg_found=0;
    while(c==1)
    {
        if(feof(inp))
        {
            break;
        }
        fread(&byte,1,1,inp);
        if(!memcmp(&byte,&a,1))
        {
        fseek(inp,-1,SEEK_CUR);
        fread(b,sizeof(header),1,inp);
        *(b+3*sizeof(uint8_t)) = *(b+3*sizeof(uint8_t)) & 0xe0;
        if(!memcmp(&a,b,sizeof(header)))
        {
            sprintf(title,"%03d.jpg",i++);
            FILE *out = fopen(title, "w");
            if (out == NULL)
            {
                fclose(out);
                fprintf(stderr, "Error");
                return 3;
            }
            fseek(inp,-4,SEEK_CUR);
            memset(&img,0,sizeof(fat));
            while(1)
            {
                if(feof(inp))
                {
                    break;
                }
                c=fread(&img,sizeof(fat),1,inp);
                if(memcmp(&img,&a,sizeof(header)) || jpg_found==0)
                {
                c=fwrite(&img,sizeof(fat),1,out);
                jpg_found++;
                }
                else
                {
                    fseek(inp, -512, SEEK_CUR);
                    break;
                }
            }
            fclose(out);
            jpg_found = 0;
        }

        }
    }
    fclose(inp);
    free(b);
}