How does fread know when the file is over in C?

Question

So I\'m not entirely sure how to use fread. I have a binary file in little-endian that I need to convert to big-endian, and I don\'t know how to read the file. Here is what

Answer 1

FILE* file = fopen(filename, "rb");
char buffer[4];

if (!file) {
/* File was opened successfully. */

/* Attempt to read */
while (fread(buffer, 1, 4, file) != EOF) {
    /* byte swap here */
}

fclose(file);
}

Answer 2

That's not how you properly read from a file in C.

fread returns a size_t representing the number of elements read successfully.

FILE* file = fopen(filename, "rb");
char buffer[4];

if (file) {
    /* File was opened successfully. */

    /* Attempt to read */
    while (fread(buffer, 1, 4, file) == 4) {
        /* byte swap here */
    }

    fclose(file);
}

As you can see, the above code would stop reading as soon as fread extracts anything other than 4 elements.