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From: "John P. Linderman" <jpl.jpl@gmail.com>
To: Warner Losh <imp@bsdimp.com>
Cc: The Unix Heritage Society <tuhs@minnie.tuhs.org>
Subject: Re: [TUHS] Command line options and complexity
Date: Thu, 12 Mar 2020 08:57:09 -0400	[thread overview]
Message-ID: <CAC0cEp_fQsq6-EaG-nhvXTvZij+PSab5PNTEx7WhNjYwnFVnaw@mail.gmail.com> (raw)
In-Reply-To: <CANCZdfp7=ZuS+enkrCa1zxBDhE-hAbKXFaiHkV_vTAe8tqGNYA@mail.gmail.com>

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My error. I was looking at getopt(1) rather than getopt(3). Of course
optind is documented, it's the way to find non-flag arguments.

I don't know why the Hancock authors chose to make rsort into a subroutine
rather than just piping into the command. Perhaps something to do with the
software release process?

On Wed, Mar 11, 2020 at 5:29 PM Warner Losh <imp@bsdimp.com> wrote:

>
>
> On Wed, Mar 11, 2020 at 11:43 AM John P. Linderman <jpl.jpl@gmail.com>
> wrote:
>
>> This is *great*, Kurt. The source in src/runtime/hrs/src for rsort.c is
>> their version of my external sort, modified to be a subroutine. There's
>> some lessons to be learned about "software hygiene". I was cavalier about
>> freeing what I allocated dynamically. As a result, their version leaks like
>> a sieve if the subroutine is called repeatedly. Apropos of which, they came
>> to me having noted that only the first call was acting as expected. There's
>> a wonderful irony (I'm big on irony). I had replaced my do-it-yourself
>> argument processing with getopt. The code has the following comment
>>
>> ** Use getopt() for portability.
>>
>> A few lines later, you see
>>
>>     optind = 1;  /* reset after use in Hancock program *
>>     while ((c = getopt(argc, argv, "cCiIjmrsSuvb:f:D:o:p:T:x:y:z:")) !=
>> EOF) {
>>
>> optind??? Seems getopt has an undocumented global flag to prevent
>> reprocessing the arguments. How portable:-)
>>
>
> It's documented:
>
>      The variables opterr and optind are both initialized to 1.  The optind
>      variable may be set to another value before a set of calls to
> getopt() in
>      order to skip over more or less argv entries.
>
> is what the FreeBSD man page has to say about it. So this just resets any
> scanning that had happened before this...
>
> Warner
>

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  parent reply	other threads:[~2020-03-12 12:58 UTC|newest]

Thread overview: 68+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-04 14:06 Nelson H. F. Beebe
2020-03-04 16:17 ` John P. Linderman
2020-03-04 17:25   ` Bakul Shah
2020-03-05  0:55   ` Rob Pike
2020-03-05  2:05   ` Kurt H Maier
2020-03-05  4:17     ` Ken Thompson via TUHS
2020-03-05 14:53       ` Dan Cross
2020-03-05 21:50       ` Dave Horsfall
2020-03-05 21:56         ` Warner Losh
2020-03-08  5:26           ` Greg 'groggy' Lehey
2020-03-08  5:32             ` Jon Steinhart
2020-03-08  9:30               ` Tyler Adams
     [not found]                 ` <CAC0cEp8eFRkkLTw88WVaKZoKy+qsrhuC8LkzmmsbqtdZgMf8eQ@mail.gmail.com>
     [not found]                   ` <CAEuQd1D7+dfap98AwPo2W41+06prrcVaAWk3Ve-ve0uQ0xBu3Q@mail.gmail.com>
2020-03-09 21:06                     ` John P. Linderman
2020-03-09 21:22                       ` Kurt H Maier
2020-03-11 17:41                         ` John P. Linderman
2020-03-11 21:29                           ` Warner Losh
2020-03-12  0:13                             ` John P. Linderman
2020-03-12  0:34                               ` Chet Ramey
2020-03-12 12:57                             ` John P. Linderman [this message]
2020-03-12 19:24                               ` Steffen Nurpmeso
2020-03-08  9:51             ` Michael Kjörling
  -- strict thread matches above, loose matches on Subject: below --
2020-03-13 10:45 Dave Horsfall
2020-03-14  4:35 ` Greg 'groggy' Lehey
2020-03-14 19:52   ` John P. Linderman
2020-03-14 20:25     ` Steffen Nurpmeso
2020-03-10 18:42 Doug McIlroy
2020-03-10 19:38 ` Dan Cross
2020-03-10 16:15 Doug McIlroy
2020-03-10 17:38 ` Dan Cross
2020-03-10 17:44   ` Bakul Shah
2020-03-10 18:09     ` Dan Cross
2020-03-05  4:57 Doug McIlroy
2020-03-05 22:17 ` Diomidis Spinellis
2020-03-03 18:15 Jon Steinhart
2020-03-03 18:44 ` Adam Thornton
2020-03-04  4:11   ` Tyler Adams
2020-03-04  6:03     ` Dave Horsfall
2020-03-04  6:48       ` arnold
2020-03-04 21:17         ` Dave Horsfall
2020-03-05  0:49         ` Lyndon Nerenberg
2020-03-05 20:54           ` Dave Horsfall
2020-03-05 22:01             ` William Cheswick
2020-03-04 21:50   ` Random832
2020-03-04 23:19     ` Steffen Nurpmeso
2020-03-05  6:12     ` Alan D. Salewski
2020-03-04 22:03   ` Random832
2020-03-04 23:25     ` Terry Jones
2020-03-10 23:03 ` Dan Stromberg
2020-03-11  3:18   ` Dave Horsfall
2020-03-11  4:02     ` Steve Nickolas
2020-03-11 22:56     ` Greg 'groggy' Lehey
2020-03-11 23:14       ` Dan Cross
2020-03-12  0:42         ` Greg 'groggy' Lehey
2020-03-12  0:53       ` Steve Nickolas
2020-03-12  3:09         ` Greg 'groggy' Lehey
2020-03-12  3:34           ` Steve Nickolas
2020-03-13  1:02             ` Greg 'groggy' Lehey
2020-03-12  5:38         ` Dave Horsfall
2020-03-12  6:48         ` Peter Jeremy
2020-03-12  7:37           ` Steve Nickolas
2020-03-12  7:42             ` Warner Losh
2020-03-12 23:57           ` Greg 'groggy' Lehey
2020-03-12  5:22       ` Dave Horsfall
2020-03-12  5:35         ` Steve Nickolas
2020-03-13  0:36         ` Greg 'groggy' Lehey
2020-03-13 11:26           ` Dave Horsfall
2020-03-14  2:13           ` Greg A. Woods
2020-03-14  4:31             ` Greg 'groggy' Lehey

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