# Reading binary file written by C program **URL:** \ **Category:** Ruby\ **Created:** [March 22, 2007, 8:28pm UTC](https://www.ruby-forum.com/t/reading-binary-file-written-by-c-program/89798 "2007-03-22T20:28:17Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Yacao\_Wang](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/bcef8e/32.png) [@Yacao\_Wang](https://www.ruby-forum.com/u/Yacao_Wang)\ **Post date:** [March 22, 2007, 8:28pm UTC](https://www.ruby-forum.com/t/reading-binary-file-written-by-c-program/89798/1 "2007-03-22T20:28:17Z")
Hi all, I’ve learned some basic of Ruby and I need to write a program that can read data from binary files written by a C program. I was supposed to use the company library to do this using C++ but I really feel that this job could be done more quickly with the advanced features of Ruby. The binary files are generally directly dumped by C structs. Is there a “ruby way” of doing this? Thanks in advance. ---
**Author:** ![Yacao\_Wang](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/bcef8e/32.png) [@Yacao\_Wang](https://www.ruby-forum.com/u/Yacao_Wang)\ **Post date:** [March 22, 2007, 8:37pm UTC](https://www.ruby-forum.com/t/reading-binary-file-written-by-c-program/89798/2 "2007-03-22T20:37:18Z")
I would start here: [http://raa.ruby-lang.org/search.rhtml?search=binary](http://raa.ruby-lang.org/search.rhtml?search=binary) (Also, check on [rubyforge.org](http://rubyforge.org)) You might want to look at Array#pack and String#unpack. Also, make sure to open up the file as binary! Enjoy. ---
**Author:** ![Yacao\_Wang](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/bcef8e/32.png) [@Yacao\_Wang](https://www.ruby-forum.com/u/Yacao_Wang)\ **Post date:** [March 22, 2007, 10:02pm UTC](https://www.ruby-forum.com/t/reading-binary-file-written-by-c-program/89798/3 "2007-03-22T22:02:30Z")
On 3/22/07, Paul S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > I would start here: > [http://raa.ruby-lang.org/search.rhtml?search=binary](http://raa.ruby-lang.org/search.rhtml?search=binary) > (Also, check on [rubyforge.org](http://rubyforge.org)) in there you will see the binary-parse gem, I wrote it to do exactly what you are describing for my own needs. pth ---
**Author:** ![Yacao\_Wang](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/bcef8e/32.png) [@Yacao\_Wang](https://www.ruby-forum.com/u/Yacao_Wang)\ **Post date:** [March 22, 2007, 10:05pm UTC](https://www.ruby-forum.com/t/reading-binary-file-written-by-c-program/89798/4 "2007-03-22T22:05:32Z")
On Fri, 23 Mar 2007, Yacao Wang wrote: > Hi all, > > I’ve learned some basic of Ruby and I need to write a program that can read > data from binary files written by a C program. I was supposed to use the > company library to do this using C++ but I really feel that this job could > be done more quickly with the advanced features of Ruby. The binary files > are generally directly dumped by C structs. Is there a “ruby way” of doing > this? Thanks in advance. look for joel’s bitstruct on rubyforge -a ---
**Author:** ![Yacao\_Wang](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/bcef8e/32.png) [@Yacao\_Wang](https://www.ruby-forum.com/u/Yacao_Wang)\ **Post date:** [March 22, 2007, 10:49pm UTC](https://www.ruby-forum.com/t/reading-binary-file-written-by-c-program/89798/5 "2007-03-22T22:49:43Z")
On 3/22/07, removed\_email\_address@domain.invalid [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > look for joel’s bitstruct on rubyforge > > ## -a > > be kind whenever possible… it is always possible. > > - the dalai lama Which is a fast, better solution for simple structures, binary-parse can handle very complex nested structures, arrays and the like. pth