jpeg-recovery.c

   1 /*
   2  * A really stupid jpeg file recover for Linux.
   3  *
   4  * You do not want to use this, you want to use photorec instead:
   5  *
   6  *      http://www.cgsecurity.org/wiki/PhotoRec
   7  *
   8  * This program is licensed under the GPLv2.
   9  *
  10  * Luiz Fernando N. Capitulino
  11  * <lcapitulino@gmail.com>
  12  */
  13 #include <stdio.h>
  14 #include <fcntl.h>
  15 #include <unistd.h>
  16 #include <stdlib.h>
  17 #include <sys/types.h>
  18 #include <sys/stat.h>
  19
  20 // Start of Image, according to the spec
  21 #define IMG_START 0xd8ff
  22
  23 // End of Image, according to hexdump :P
  24 // Some images do not have the EOI specified by the standard (0xffd9),
  25 // the value bellow worked for a lot of images.
  26 #define IMG_END 0xff3f
  27
  28 static int open_file(void)
  29 {
  30         char filename[12];
  31         static int counter = 0;
  32
  33         snprintf(filename, sizeof(filename), "img%d.jpeg", counter++);
  34         return open(filename, O_RDWR | O_CREAT, 0444);
  35 }
  36
  37 int main(int argc, char *argv[])
  38 {
  39         ssize_t bytes;
  40         unsigned short c;
  41         int found, amount, fd, fd2;
  42
  43         if (argc != 2) {
  44                 fprintf(stderr, "you have to specify the device name\n");
  45                 exit(1);
  46         }
  47
  48         fd = open(argv[1], O_RDONLY);
  49         if (fd < 0) {
  50                 perror("open()");
  51                 exit(1);
  52         }
  53
  54         found = amount = 0;
  55
  56         while (read(fd, &c, 2) > 0) {
  57                 if (c == IMG_START) {
  58                         found = 1;
  59                         fd2 = open_file();
  60                         if (fd2 < 0) {
  61                                 perror("open_file()");
  62                                 exit(1);
  63                         }
  64                         fprintf(stderr, "Found %d\r", amount++);
  65                 }
  66
  67                 if (found) {
  68                         bytes = write(fd2, &c, 2);
  69                         if (bytes < 0) {
  70                                 perror("write()");
  71                                 exit(1);
  72                         }
  73
  74                         if (c == IMG_END) {
  75                                 close(fd2);
  76                                 found = 0;
  77                         }
  78                 }
  79         }
  80
  81         fprintf(stderr, "\n");
  82         return 0;
  83 }