This C program written for course work recovers deleted images from an image card file.

recover.c

#include <stdio.h>

#include <stdlib.h>

#include <string.h>



int main(int argc, char *argv[])

{

    if (argc != 2)

    {

        fprintf(stderr, "Usage: ./recover image");

        return 1;

    }



    // remember file names

    char *image = argv[1];



    // open image card file

    FILE *imgptr = fopen(image, "r");

    if (imgptr == NULL)

    {

        fprintf(stderr, "Could not open %s.\n", image);

        return 2;

    }



    // check if we found the first jpeg

    int foundjpeg = 0; // false



    // counter for number of jpegs found on memory card

    int numjpegs = 0;



    // assign variable for jpeg filename

    char filename[8] = {0};



    // jpeg file pointer

    FILE* img;



    // create buffer

    unsigned char buffer[512];



    // repeat until end of card. I may need to divide sizeof(imgptr)

        while(fread(buffer, 512, 1, imgptr) == 1)

        {

            if (buffer[0] == 0xff &&

                buffer[1] == 0xd8 &&

                buffer[2] == 0xff &&

                (buffer[3] & 0xf0) == 0xe0)

            {

                // we found a JPEG

                foundjpeg = 1;

                // already found a JPEG?

                if (numjpegs == 0)

                {

                    // no =>

                    // start first jpeg

                    sprintf(filename, "%03i.jpg", numjpegs);

                    img = fopen(filename, "w");

                    numjpegs++;

                }

                else

                {

                    // yes =>

                    // close previous file and open our new one

                    fclose(img);

                    sprintf(filename, "%03i.jpg", numjpegs);

                    img = fopen(filename, "w");

                    numjpegs++;

                }

            }

            if (foundjpeg == 1)

            {

            // write 512 bytes to new jpeg file

            fwrite(&buffer, 512, 1, img);

            }

        }



    // exit loop and close any remaining files.

    fclose(imgptr);

    fclose(img);



    // success

    return 0;



}