I am building a PE-COFF file reader, just for education purposes, and I keep getting a ConvException come up, stating:

---

  Unexpected '

---

Now, I have no idea how I'm getting this. The code at that point looks like the following:

---

  // look for the identifier
  // this gives us the offset to the magic number
  uint offs;
  file.seek(0x3c, SEEK_SET);

  file.readf("%d", &offs); // this is the problem line

  writefln("magic number offset: %d", offs);
  file.seek(offs, SEEK_SET);

---

With the exception being raised on the writefln. I have the same trouble with

  writeln("magic number offset: ", offs);

and I'm not sure how to go about fixing it. About the only clue I can come up with, is that if I were to look at the section of code in the hex editor, the number at that point generates a "'", the offending character, when represented as a character array.

Does anyone else see whatever it is that I'm doing wrong?

On Friday, 3 October 2014 at 11:30:02 UTC, Matt wrote:
> I am building a PE-COFF file reader
>   file.seek(0x3c, SEEK_SET);
>   file.readf("%d", &offs); // this is the problem line
> Does anyone else see whatever it is that I'm doing wrong?

readf is for reading text, it expects to see some digits. You're reading a binary file, not a text, so no ASCII digits are found in that place. Use rawRead instead of readf.

On Friday, 3 October 2014 at 13:48:41 UTC, thedeemon wrote:
> On Friday, 3 October 2014 at 11:30:02 UTC, Matt wrote:
>> I am building a PE-COFF file reader
>>  file.seek(0x3c, SEEK_SET);
>>  file.readf("%d", &offs); // this is the problem line
>> Does anyone else see whatever it is that I'm doing wrong?
>
> readf is for reading text, it expects to see some digits. You're reading a binary file, not a text, so no ASCII digits are found in that place. Use rawRead instead of readf.

much obliged, many thanks

On Fri, 03 Oct 2014 14:19:23 +0000
Matt via Digitalmars-d-learn <digitalmars-d-learn@puremagic.com> wrote:

also you can use my iv.io module to reading binary numbers: http://repo.or.cz/w/iv.d.git/blob_plain/HEAD:/io.d

like this:

  auto offs = file.readNum!uint();

this is endian-safe too (in the sense that it assumes that file data is
little-endian).

or, if you want to do it dirty, replace your readf with this:

  file.rawRead((&offs)[0..1]);