Do you ever find yourself writing code like this?
io = File.open(...)
len = io.read(2).unpack("v")
name = io.read(len)
width, height = io.read(8).unpack("VV")
puts "Rectangle #{name} is #{width} x #{height}"It’s ugly, violates DRY and feels like you’re writing Perl, not Ruby.
There is a better way. Here’s how you’d write the above using BinData.
class Rectangle < BinData::Record
endian :little
uint16 :len
string :name, :read_length => :len
uint32 :width
uint32 :height
end
io = File.open(...)
r = Rectangle.read(io)
puts "Rectangle #{r.name} is #{r.width} x #{r.height}"BinData provides a declarative way to read and write structured binary data.
This means the programmer specifies what the format of the binary
data is, and BinData works out how to read and write data in this
format. It is an easier (and more readable) alternative to
ruby's #pack and #unpack methods.
BinData makes it easy to create new data types. It supports all the common primitive datatypes that are found in structured binary data formats. Support for dependent and variable length fields is built in.
$ gem install bindata
or if running ruby 1.8
$ gem install bindata -v '~> 1.8.0'
If you have any queries / bug reports / suggestions, please contact me (Dion Mendel) via email at bindata@dm9.info