1. #include <stdio.h>
2. #include <stdlib.h>
3. #include <cs50.h>
4.  
5. int main(int argc, char *argv[])
6. {
7.     //check command line arguments and make sure they are more than one
8.     if (argc != 2)
9.     {
10.         printf("Usage: ./recover file\n");
11.         return 1;
12.     }
13.    
14.     FILE *inptr = fopen (argv[1], "r");
15.     //if file does not exist return an error
16.     if (inptr == NULL)
17.     {
18.         printf("Error! Could not recover\n");
19.         return 2;
20.     }
21.     //create filename and buffer arrays
22.     unsigned char buffer[512];
23.     char filename[8];
24.    
25.     //set file count to 0
26.     int jpeg_count = 0;
27.     int picture = 0;
28.     int found_jpeg = 0;
29.    
30.     //new file I'll be writing to
31.     FILE* outptr = NULL;
32.  
33.         while (fread (buffer, sizeof(buffer), 1, inptr) == 1)
34.         {
35.             //find the beginning of jpg signature
36.             if (buffer[0] == 0xff && buffer[1] == 0xd8 && buffer[2] == 0xff && (buffer[3] & 0xf0) == 0xe0)
37.             {
38.                 //for first jpeg found
39.               if (jpeg_count == 0)
40.               {
41.                   sprintf (filename, "%03i.jpg", jpeg_count);
42.                   jpeg_count++;
43.                  
44.                   //open first file i.e. 000.jpg
45.                   outptr = fopen (filename, "w");
46.               }
47.               //if jpeg already found
48.               else
49.               {
50.                   //close current file that was being written to
51.                   fclose(outptr);
52.  
53.                   sprintf (filename, "%03i.jpg", jpeg_count);
54.                   jpeg_count++;
55.                   //open new file just created to start writing data into it
56.                   outptr = fopen (filename, "w");
57.                   fwrite (buffer, sizeof(buffer), 1, outptr);
58.               }
59.             }
60.            
61.           if (outptr != NULL)
62.               {
63.                   //keep writing to current file if already in open jpeg
64.                   fwrite (&buffer, sizeof(buffer), 1, outptr);
65.               }
66.         }
67.         //close input file
68.     fclose(inptr);
69.    
70.     //close output file
71.     fclose(outptr);
72.     return 0;
73. }
74.  
75.