From mboxrd@z Thu Jan  1 00:00:00 1970
From: reed@reedmedia.net (Jeremy C. Reed)
Date: Fri, 9 Apr 2010 00:35:38 -0500 (CDT)
Subject: [pups] extract old archive format?
In-Reply-To: <337550.74945.qm@web82407.mail.mud.yahoo.com>
References: <337550.74945.qm@web82407.mail.mud.yahoo.com>
Message-ID: <alpine.NEB.2.01.1004090033570.13963@t1.m.reedmedia.net>

On Thu, 8 Apr 2010, Michael Davidson wrote:

> Your modern compiler is almost certainly inserting two bytes of padding
> after ar_name[]
> so that the int32_t ar_date is aligned on a 4 byte boundary - that shifts
> everything else
> down by 2 bytes and means that ar_size lines up with the last 2 bytes of the
> size in
> the header which, as luck would have it, is the low order 16 bits of the
> size as it would
> have been stored in a 32 bit long.
> 
> Something like this should work on a modern little endian processor"
> 
> struct {
>         char    ar_name[14];
>         int16_t ar_date_16_31;
>         int16_t ar_date_00_15;
>         char    ar_uid;
>         char    ar_gid;
>         uint16_t        ar_mode;
>         uint16_t        ar_size_16_31;
>         uint16_t        ar_size_00_15;
> } ar_buf;

Thank you! That works for me! I can now get correct sizes, names, and 
data. I will clean up my little ar extractor over the next few days and 
share it.