[TUHS] v7, adb, and fcreat

Will Senn will.senn at gmail.com
Thu Aug 6 22:15:25 AEST 2020

Thanks, John. That is one concise answer that explains the problem quite 
well. Now that I think about it, it explains quite a bit about quite a 
bit :).


On 8/6/20 12:00 AM, John Cowan wrote:
> The manual came out in editions, but the code, man pages, etc. changed 
> continuously.  So what you hear about in a particular paper is not 
> necessarily correlated with a particular state of the manual.
> On Thu, Aug 6, 2020 at 12:49 AM Will Senn <will.senn at gmail.com 
> <mailto:will.senn at gmail.com>> wrote:
>     I've done research on this, but I'm confused and would appreciate
>     some help to understand what's going on. In the 7th edition
>     manual, vol 2, there's an ADB tutorial (pp. 323-336). In the
>     tutorial, the authors, Maranzano and Bourne, walk the reader
>     through a debugging session. The first example is predicated on a
>     buffer overflow bug and the code includes:
>     struct buf {
>     int fildes;
>     int nleft;
>     char *nextp; char buff[512]; }bb;
>     struct buf *obuf;
>     ...
>     if((fcreat(argv[1],obuf)) < 0){
>     ...
>     Well, this isn't v7 code. As discussed in the v7 manual vol 1 (p.
>     VII):
>     Standard I/O. The old fopen, getc, putc complex and the old –lp
>     package are both dead, and even getchar has changed. All have been
>     replaced by the clean, highly efficient, stdio(3) package. The
>     first things to know are that getchar(3) returns the integer EOF
>     (–1), which is not a possible byte value, on end of file, that
>     518-byte buffers are out, and that there is a defined FILE data type.
>     The buffers are out, fcreat is gone, etc. So, what's up with this?
>     I don't think adb was in v6, where the fcreat function and buf
>     struct are used... Were Maranzano and Bourne using some kind of
>     hybrid 6+ system?
>     Thanks,
>     Will
>     -- 
>     GPG Fingerprint: 68F4 B3BD 1730 555A 4462  7D45 3EAA 5B6D A982 BAAF

GPG Fingerprint: 68F4 B3BD 1730 555A 4462  7D45 3EAA 5B6D A982 BAAF

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