fgetc Reading 65535 is 255?

So I've started writing my assembler now was just doing some little tests to determine the best way to read / write the words (unsigned short's typedef'd).

So far I have this:

Code:

---

int main(int argc, char* argv[])
{
    FILE* f = fopen("PROGRAM.lvmp", "w");
    word instruction[3] = {0};

    cout << "instruction: ";
    cin >> instruction[0];
    cin >> instruction[1];
    cin >> instruction[2];

    fputc(instruction[0], f);
    fputc(instruction[1], f);
    fputc(instruction[2], f);

    fclose(f);

    f = fopen("PROGRAM.lvmp", "r");

    instruction[0] = fgetc(f);
    instruction[1] = fgetc(f);
    instruction[2] = fgetc(f);
    fclose(f);

    cout << "opcode: " << instruction[0] << "\n";
    cout << "op1: " << instruction[1] << "\n";
    cout << "op2: " << instruction[2] << endl;
    return 0;
}

---

It works fine unless I enter something like

Code:

---

3 10 65531

---

(movl 10, r0)

In which case when fgetc reads it I get this output:

Code:

---

opcode: 3
op1: 10
op2: 251

---

If I give it 65535 (OP_END) op2 is read as 255. I can only guess that this is happening due to something to do with ASCII. How could I get around this? fgetc / fputc is probably not the best choice anyway.

Thoughts?

> fputc(instruction[2], f);
My thought is that you should write the LSB and MSB of your word.

You should also probably use "rb" and "wb"

Noted.

EDIT:

>> My thought is that you should write the LSB and MSB of your word.

Sorry, can you explain why and how? :(

EDIT2: Actually don't tell me (yet. Perhaps) I've found a few articles and think I might have it in a minute.

EDIT3: Well now I know why, but I'm still a bit stuck on how to actually do it.

Like
fputc(instruction[0] & 0xff, f);
fputc((instruction[0]>>8)&0xff, f);

I just solved it as I saw your reply :cool:

Here's what I had but looking at yours it's a bit OTT:

Code:

---

int main(int argc, char* argv[])
{
    FILE* f = fopen("PROGRAM.lvmp", "wb");
    word instruction[3] = {0};
    byte opcodeLSB;
    byte opcodeMSB;

    cout << "instruction: ";
    cin >> instruction[0];

    opcodeMSB = instruction[0] & 255;
    opcodeLSB = (instruction[0] >> 8) & 255;

    fputc(opcodeLSB, f);
    fputc(opcodeMSB, f);
    fclose(f);

    f = fopen("PROGRAM.lvmp", "rb");

    opcodeMSB = fgetc(f);
    opcodeLSB = fgetc(f);
    instruction[0] = (opcodeMSB << 8) + opcodeLSB;

    fclose(f);

    cout << "opcode: " << instruction[0] << "\n";
    return 0;
}

---

Cheers to you and http://www.gamedev.net/reference/art...rticle2091.asp

Or just use fread() and fwrite() to save the whole array in one shot.

Or fputwc :D

After all that? Bah, at least I learnt something.