From: Eric Hodel <drbrain@...7.net>
Date: 2006-02-22T15:27:52+09:00
Subject: Re: Question about String.unpack

On Feb 21, 2006, at 6:28 AM, Eric Jacoboni wrote:

> Say i've a C struct like that:
>
> typedef struct {
>   char name[30];
>   double size;
>   int age;
>   char stuff;
> } enreg_t;
>
> This record is written in a file that i want to re-read with a Ruby
> script (just a toy example... to understand).
>
> I've not found a "clean" way to unpack such a record...
>
> My C compiler gives me a total sizeof of 48, so i use a
>   fd.sysread(48).unpack(A32dIC) to re-read. But that seems rather

Your struct says char name[30] not 32...

>   'tricky' (i suppose we don't have always such a
>   information). Furthermore, the first element is completed with
>   garbage if the name field have less than 30 "useful" chars ("Doe",
>   for example).

Did you initialize the C struct correctly?  You should zero out all  
of name.

> I'm sure i'm missing something but i've not managed to find the right
> way to do that.

-- 
Eric Hodel - drbrain@segment7.net - http://segment7.net
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