From: brabuhr@...
Date: 2009-09-03T00:12:17+09:00
Subject: Re: confusing string parsing problem

On Wed, Sep 2, 2009 at 10:01 AM, Matt Brooks<mattbrooks@gatech.edu> wrote:
> I don't understand how to do the following, any help is very
> appreciated.  I have been programming in ruby 1.8.7 for about a month.
>
> I have a string that has in it:
> 2 byte UINT16
> 2 byte UINT16
> 1 byte UINT8 representing how many pairs of the next 2 strings there are
> variable length string1 <- Although for now I know this always equals
> BFO
> variable length string2
> 2 byte UINT16
>
> I want to display each value from the fields, while also removing it
> from the string as I read it out...
>
> My attempt is horrible I know, and I don't think it really runs.

Can you post an example of your data and code with the incorrect
output and expected output?

> cat z.rb
string = ""
string << 0.chr << 1.chr
string << 0.chr << 2.chr
string << 2.chr
string << "foo" << "BFO"
string << "bar" << "BFO"
string << 0.chr << 3.chr

p string

p string[0..1], string[0..1].unpack('n')
p string[2..3], string[2..3].unpack('n')
p string[0..3].unpack('n2')

p string[4..4], string[4..4].unpack('C')
p string[0..4].unpack('n2C')

p string[5..-2].split(/BFO/)

> ruby -v z.rb
ruby 1.8.7 (2008-08-11 patchlevel 72) [i486-linux]
"\000\001\000\002\002fooBFObarBFO\000\003"
"\000\001"
[1]
"\000\002"
[2]
[1, 2]
"\002"
[2]
[1, 2, 2]
["foo", "bar", "\000"]