Article View: comp.text
Article #4617Re: pic bug (not quite)
From: Brent Byer
Date: Fri, 15 Apr 1988 16:33
Date: Fri, 15 Apr 1988 16:33
53 lines
2653 bytes
2653 bytes
In article <921@hsi.UUCP> stevens@hsi.UUCP (Richard Stevens) writes:
>I've encountered the following bug in pic, and was wondering if
>anyone has a fix. I'm using the pic that came with DWB 2.0.
>
>Arrows in pic that go straight down or straight up have the head
>of the arrow shifted slightly to the left. For example,
>
> | |
> | |
> \ | / \| /
> \|/ \ /
>
> correct this is what the bug produces (exaggerated)
( I believe you will find the glitch factor to be even worse
on angled shafts. )
The bug is not really in pic; anal analysis of pic's output
will show it to be correct. So, the problem is actually
in some combination of ditroff and your post-processor.
>The bug appears to be in the latest AT&T Release (i.e., DWB 2.0),
>as I've found, [see also p. 345 of Bach "The Design of the UNIX
>Operating System"] but was fixed sometime in Version 8 [see p. 313
>of Kernighan and Pike for the bug, but see also p. 111 of Bentley's
>"Programming Pearls" for a fixed version] and is fixed in Version 9
>[see p. 173 of "The AWK Programming Language" by A. K. and W.].
The above observations appear valid, but because of the *actual*
nature of the problem, it may very well not have been fixed at all.
>Does anyone have a fix ?? Thanks.
Since Textware endeavors to deliver high-quality software to a
hopefully fussy audience, we have fixed this (and quite a few
other pic-related doo-dahs) in our Tplus product. Remember, just
because a vendor *advertises* "full support for pic" doesn't mean they
are capable of delivering.
It's because of this tighter-than-you-thought inter-relationship of
{ pre-processors, formatter, and post-processor } that we recommend
that users get the entire set-up from a single (binary?) source.
Otherwise, support for a problem like this can be a futile nightmare.
> Richard Stevens
> Health Systems International, New Haven, CT { uunet | ihnp4 } ! hsi ! stevens
Brent Byer { ihnp4!ihesa , harvard!cca } !textware!brent
Textware Intl.
PO 14 - Harv Sq
Cambridge, MA 02238
(617) 864-8398 (uni-text)
"Leaners don't count, in typesetting."
Technical Details
Message-ID:
<197@wjh12.harvard.edu>Path:
arc1-ca.pugleaf.net!utzoo!mnetor!uunet!husc6!wjh12!bbReferences:
<921@hsi.UUCP>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!mnetor!uunet!husc6!wjh12!bb From: bb@wjh12.harvard.edu (Brent Byer) Newsgroups: comp.text Subject: Re: pic bug (not quite) Message-ID: <197@wjh12.harvard.edu> Date: 15 Apr 88 16:33:49 GMT References: <921@hsi.UUCP> Reply-To: bb@wjh12.UUCP (Brent Byer) Organization: Textware Intl., Cambridge MA Lines: 53 Keywords: pic