From: daz <dooby@...10.karoo.co.uk>
Date: 2004-04-25T14:34:03+09:00
Subject: Re: String#unpack and null-terminated strings


Michael Neumann wrote:
> Hi,
>
> How can I unpack two or more consecutive C-strings with the
> String#unpack method? Like this:
>
>   "abc\000def\000".unpack("??") # => ["abc", "def"]
>
> Currently, this seems not to be possible. Any chance to get the
> following patch applied, which implements exactly this?
>
> [snip] diff -r1.69 pack.c


At the risk of being told to clear off and write my own spec.,
I think that an ambuiguity has intruded into the designers mind.

The A and Z string field formats should IMO be recovered from
left to right.  Doesn't the term "string" relate here to a
string element within a packed field.  The packed field just
happens to be a Ruby String.

If this is going to break code, I wish that it could happen
from 1.9.
As it is now, A and Z are behaving the way I would expect
A* and Z* to (i.e. * uses all remaining elements).

There's String#rstrip for removing spaces and nulls from the
end of a String.

Unpack is very useful for decoding structures but with the
current behaviour if a structure were to contain a null-
terminated string element it would break the flow ...
.... as Michael has highlighted.

Please, Matz.


daz