After spending almost a week working on the code for the Recover exercise, I have finally made it work. However, when I check with check50, I get the error: :( program is free of memory errors timed out while waiting for program to exit.
I know that I could probably find what's wrong by using the debug50 debugger, but for some reason it won't work. Now, regarding the error, the magic duck says that there is probably a loop in my program that never exits.
I' m looking at it for quite some time. I tried changing things here and there, but the only thing I actually managed to do was to break the code, so I had to fix it again and again, without getting rid of the memory error.
I would be glad if someone could help me with this. Here's my code:
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
// Let's avoid typing magic numbers!
#define FAT_FILE_BLOCK_SIZE 512
#define FILENAME_LENGTH 8
typedef uint8_t BYTE;
int main(int argc, char *argv[])
{
// Accept a single command-line arguement
if (argc != 2)
{
printf("Usage: ./recover <insert filename here>\n");
return 1;
}
// Open the memory card
FILE *card = fopen(argv[1], "r");
if (card == NULL)
{
printf("Unable to open file.\n");
return 1;
}
BYTE *buffer = malloc(sizeof(BYTE) * FAT_FILE_BLOCK_SIZE);
if (buffer == NULL)
{
fclose(card);
printf("Unable to store jpeg.\n");
return 1;
}
int counter = 0;
char new_jpeg_name[FILENAME_LENGTH];
FILE *jpeg = NULL;
// While there's still data left to read from the memory card
while ((fread(buffer, sizeof(buffer), 1, card)) == 1)
{
// Check header for JPEG file
if (buffer[0] == 0xff && buffer[1] == 0xd8 && buffer[2] == 0xff && (buffer[3] & 0xf0) == 0xe0)
{
if (counter > 0)
{
fclose(jpeg);
}
sprintf(new_jpeg_name, "%03i.jpg", counter);
counter++;
jpeg = fopen(new_jpeg_name, "a");
}
if (counter > 0)
{
fwrite(buffer, sizeof(buffer), 1, jpeg);
}
}
if (jpeg != NULL)
{
fclose(jpeg);
}
fclose(card);
free(buffer);
return 0;
}
