pset 4 - recover - fread keeps returning 0 when reading 512 bytes on buffer?

Question

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

typedef uint8_t  BYTE;

int main(int argc, char* argv[])
{ 
    // checks proper user input on command line
    if (argc != 2)
    {
        fprintf(stderr, "Usage: ./recover image\n");
        return 1;
    }
    // opens .raw file and checks for errors
    FILE *inptr = fopen(argv[1], "r");
    if (inptr == NULL)
    {
        fprintf(stderr, "Could not open file\n");
        return 2;
    }

    // creates buffer to store 512 bytes
    BYTE buffer[512];
    // keeps track of jpegs found
    int jpegCount = 0;
    // initializes filename and file variables for writing
    char filename[8];
    FILE *currentjpeg;
    // repeats until EOF
    while (fread(buffer, 1, sizeof(buffer), inptr) == 512)
    {
         // do stuff
    }
    fclose(inptr);
}

The debugger says fread returns 0 on the while condition (I checked by making a few variables) and I don't understand why.

Answer 1

I tested with your code and it's definitely correct, as @cliff has said in the commment. Do make sure the file you are opening actually has more than 512 bytes. Perhaps your rawfile has been corrupted?