# Weird error while reading binary files **URL:** \ **Category:** Ruby\ **Created:** [December 22, 2006, 3:24am UTC](https://www.ruby-forum.com/t/weird-error-while-reading-binary-files/80203 "2006-12-22T03:24:38Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![kishi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/f17d59/32.png) [@kishi](https://www.ruby-forum.com/u/kishi)\ **Post date:** [December 22, 2006, 3:24am UTC](https://www.ruby-forum.com/t/weird-error-while-reading-binary-files/80203/1 "2006-12-22T03:24:38Z")
Hello everyone! I just started messing around with Ruby and so far it’s been great. Somehow I’ve stepped into some weird error I can’t understand nor solve it… I’ve been trying to google about it but with no results… Here’s what’s going on: I’ve got a file structure which is like: 4 bytes - Number of entries For number of entries : 300 bytes of information… several integers, longs, floats, strings… If I do: theFile = File.open(‘FilePath’) infoArray = Array.new infoEntries = theFile.read(4).unpack(‘V’)[0] infoEntries.times do |i| infoArray[i] = theFile.read(300).unpack(‘VA4V2FS4V12A24A8A32A32A32A32A32V8’) end It will go fine until infoArray[33]. After that it won’t work at all! Let me make myself clear: irb(main):002:0\> theFile = File.open(‘FILEPATH’) =\> #\ irb(main):003:0\> theFile.pos = 10244 =\> 10244 irb(main):004:0\> theFile.read(4) =\> “H\001\000\000” irb(main):005:0\> theFile.pos =\> 14340 irb(main):006:0\> See how it jumped positions?! That’s odd… Is there a file-size limit or something like that? I’m under Windows, by the way… ---
**Author:** ![kishi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/f17d59/32.png) [@kishi](https://www.ruby-forum.com/u/kishi)\ **Post date:** [December 22, 2006, 3:30am UTC](https://www.ruby-forum.com/t/weird-error-while-reading-binary-files/80203/2 "2006-12-22T03:30:08Z")
I’ve tested it with and without unpack… Several files… And nothing. I haven’t tested the BinaryStructure thing class yet… But I don’t feel like using it… It shouldn’t be needed, at least. Thanks! [sorry about the double post, accidentaly posted it before finishing it] ---
**Author:** ![kishi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/f17d59/32.png) [@kishi](https://www.ruby-forum.com/u/kishi)\ **Post date:** [December 22, 2006, 4:26am UTC](https://www.ruby-forum.com/t/weird-error-while-reading-binary-files/80203/3 "2006-12-22T04:26:30Z")
Mauricio Kishi wrote: > theFile = File.open(‘FilePath’) On windows, you’ll want theFile = File.open(‘FilePath’, “rb”) to put the file in binary mode (doesn’t convert \r\n to \n). ---
**Author:** ![kishi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/f17d59/32.png) [@kishi](https://www.ruby-forum.com/u/kishi)\ **Post date:** [December 22, 2006, 4:31am UTC](https://www.ruby-forum.com/t/weird-error-while-reading-binary-files/80203/4 "2006-12-22T04:31:28Z")
Joel VanderWerf wrote: > Mauricio Kishi wrote: > > > theFile = File.open(‘FilePath’) > > On windows, you’ll want > > theFile = File.open(‘FilePath’, “rb”) > > to put the file in binary mode (doesn’t convert \r\n to \n). OMG! No! Somehow I’ve missed it on the newest .rb files… O\_O" Thanks a lot… And sorry for such a stupid thing. ---
**Author:** ![kishi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/f17d59/32.png) [@kishi](https://www.ruby-forum.com/u/kishi)\ **Post date:** [December 22, 2006, 4:28am UTC](https://www.ruby-forum.com/t/weird-error-while-reading-binary-files/80203/5 "2006-12-22T04:28:10Z")
Joel VanderWerf wrote: > Mauricio Kishi wrote: > > > theFile = File.open(‘FilePath’) > > On windows, you’ll want > > theFile = File.open(‘FilePath’, “rb”) > > to put the file in binary mode (doesn’t convert \r\n to \n). Ooops, that was a mistake while writing the post! I’m already opening the files on binary mode…