From: Matt Brooks <mattbrooks@...>
Date: 2009-09-03T01:09:54+09:00
Subject: Re: confusing string parsing problem

unknown wrote:
> On Wed, Sep 2, 2009 at 10:01 AM, Matt Brooks<mattbrooks@gatech.edu> 
> wrote:
>> 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"]


Thanks a lot for your reply, i will look into it and see if i can 
implement using unpack.  in the meantime this is a sample output...



My current output is:
              1st 2 byte field = 3
              2nd 2 byte field = 0
                     Num Pairs = 1
sub_elements = 
"BFO\0000\000\000\000\001\000\000\0005\000\003\000\000\000\00
0\000\000\000\000\000\001\002\000\000\312+\335V\353\262\000\001\001Internal...and 
so on for hundreds of bytes more...
I, [2009-09-02 11:56:10 #4864]  INFO -- : Pairs to get: 1
I, [2009-09-02 11:56:10 #4864]  INFO -- : Param Value Name: BFO


what i want output to be:
I, [2009-09-02 11:56:10 #4864]  INFO -- : Pairs to get: 1
I, [2009-09-02 11:56:10 #4864]  INFO -- : Param Value Name: BFO
I, [2009-09-02 11:56:10 #4864]  INFO -- : String Value: whatever the 
string is till it is null terminated
I, [2009-09-02 11:56:10 #4864]  INFO -- : Last 2 byte field: 0


And At this point I need the sub_elements string to not contain any of 
the above parameters printed out, ie. whatever I display is done with 
and needs to be deleted out of the front of the string.


my code:
I was redoing my code, and only up to this point.
#prints first 5 bytes formated nicely
  writelog("#{bin_msg.inspect_detailed})")

#How many pairs to expect
  writelog("Pairs to get: #{bin_msg.num_optional_mod_params}")

#Remove BFO while printing it as well
  writelog("Param Value Name: #{bin_msg.sub_elements.slice!(/^BFO/)}")


#THIS DOESN'T WORK!!! Needs to scan for possible minus sign, plus up to 
#variable length number of digits, up to the null termination of the 
string
  bin_msg.sub_elements.scan(/-?[0-9]+\Z/)

#Needs to then print the next 2 bytes while taking that out of the 
string as well
-- 
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