Re: Always use "--" (Was: Long filenames in DOS/Windows and Unix/Linux)

From	Kaz Kylheku <643-408-1753@kylheku.com>
Newsgroups	comp.unix.programmer
Subject	Re: Always use "--" (Was: Long filenames in DOS/Windows and Unix/Linux)
Date	2024-09-05 02:29 +0000
Organization	A noiseless patient Spider
Message-ID	<20240904192549.23@kylheku.com> (permalink)
References	(1 earlier) <yga34mfoily.fsf@akutech.de> <87ttevzoj3.fsf@nosuchdomain.example.com> <vb9k2l$3r705$1@dont-email.me> <vb9ls7$1igeo$1@news.xmission.com> <vb9mls$3rk17$1@dont-email.me>

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On 2024-09-04, Lew Pitcher <lew.pitcher@digitalfreehold.ca> wrote:
> On Wed, 04 Sep 2024 13:04:07 +0000, Kenny McCormack wrote:
>
>> In article <vb9k2l$3r705$1@dont-email.me>,
>> Nuno Silva  <nunojsilva@invalid.invalid> wrote:
>> ...
>>>> D'oh!
>>>
>>>(Along with these quotes, I'd add ./ before $file.)
>> 
>> Or, more simply, just put -- after the -p.
>> 
>> This is an often overlooked aspect of shell programing.  You should always
>> use "--".  The "shellcheck" program will tell you this, if you let it.
>
> The "--" option is just that, an option coded into the argument parser of
> the program being invoked. Many programs /do not/ recognize "--" as an
> "end of flags" argument, so the effectiveness of "--" is unreliable.
>
> OTOH, if you specify a fully qualified pathname, (or, at least, a qualified
> relative pathname), you can assure yourself that the file path provided
> to the program /will not/ start with the '-' that indicates a program flag.
>
> Note that all this is /convention/ and not /requirement/. There are situations
> in which /none/ of the above applies, as
> a) the program interprets it's arguments by /position/, or
> b) the program doesn't use the '-' to introduce flag arguments, or
> c) the program doesn't take filenames as arguments, or
> d) some other conditions that I'm too lazy to enumerate

d) it's a goddamned GNU program that continues to take options
after non-option arguments!

$ ls . -ld
drwxr-xr-x 67 kaz kaz 36864 Sep  3 15:59 .

... unless -- is specified to signal the end of options.

$ ls -ld -- . -ld
ls: cannot access '-ld': No such file or directory
drwxr-xr-x 67 kaz kaz 36864 Sep  3 15:59 .

So unfortunately although starting an argument with ./ will
ensure that it's not treated as an option, it doesn't mean
it will be treated as the first non-option argument after
which there are no more option arguments.

-- 
TXR Programming Language: http://nongnu.org/txr
Cygnal: Cygwin Native Application Library: http://kylheku.com/cygnal
Mastodon: @Kazinator@mstdn.ca

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Long filenames in DOS/Windows and Unix/Linux (Was: Piping to stdin) gazelle@shell.xmission.com (Kenny McCormack) - 2024-08-31 05:57 +0000
  Re: Long filenames in DOS/Windows and Unix/Linux Richard Kettlewell <invalid@invalid.invalid> - 2024-08-31 09:27 +0100
    Re: Long filenames in DOS/Windows and Unix/Linux Muttley@dastardlyhq.com - 2024-08-31 08:39 +0000
    Re: Long filenames in DOS/Windows and Unix/Linux Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-08-31 23:34 +0000
      Re: Long filenames in DOS/Windows and Unix/Linux Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-09-01 07:03 +0000
        Re: Long filenames in DOS/Windows and Unix/Linux Nuno Silva <nunojsilva@invalid.invalid> - 2024-09-01 09:10 +0100
        Re: Long filenames in DOS/Windows and Unix/Linux Helmut Waitzmann <nn.throttle@xoxy.net> - 2024-09-01 19:51 +0200
        Putting arbitrary characters into the shell command line (was: Long filenames in DOS/Windows and Unix/Linux) Helmut Waitzmann <nn.throttle@xoxy.net> - 2024-09-01 21:07 +0200
        Re: Long filenames in DOS/Windows and Unix/Linux Wayne <wayne@nospam.invalid> - 2024-09-03 13:56 -0400
          Re: Long filenames in DOS/Windows and Unix/Linux Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-09-03 21:54 +0000
        Re: Long filenames in DOS/Windows and Unix/Linux Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-09-08 07:24 +0200
      Arbitrary characters in filenames (was: Long filenames in DOS/Windows and Unix/Linux) Helmut Waitzmann <nn.throttle@xoxy.net> - 2024-09-01 20:06 +0200
  Re: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to stdin) Muttley@dastardlyhq.com - 2024-08-31 08:37 +0000
    Re: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to stdin) John Ames <commodorejohn@gmail.com> - 2024-09-03 08:44 -0700
      Re: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to stdin) scott@slp53.sl.home (Scott Lurndal) - 2024-09-03 15:47 +0000
        Re: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to stdin) Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2024-09-03 15:54 +0000
      Re: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to stdin) gazelle@shell.xmission.com (Kenny McCormack) - 2024-09-03 16:10 +0000
        Re: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to Muttley@dastardlyhq.com - 2024-09-04 07:27 +0000
          User surveys (Was: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to) gazelle@shell.xmission.com (Kenny McCormack) - 2024-09-04 11:27 +0000
            Re: User surveys (Was: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to) Muttley@dastardlyhq.com - 2024-09-04 13:12 +0000
      Re: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to stdin) Kaz Kylheku <643-408-1753@kylheku.com> - 2024-09-03 17:37 +0000
        Re: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to stdin) John Ames <commodorejohn@gmail.com> - 2024-09-03 11:39 -0700
          Re: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to stdin) Kaz Kylheku <643-408-1753@kylheku.com> - 2024-09-03 20:11 +0000
            Re: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to stdin) John Ames <commodorejohn@gmail.com> - 2024-09-03 13:25 -0700
              Re: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to stdin) scott@slp53.sl.home (Scott Lurndal) - 2024-09-03 20:34 +0000
                Re: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to stdin) Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-09-03 21:52 +0000
              Re: Long filenames in DOS/Windows and Unix/Linux Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-09-03 15:16 -0700
                Re: Long filenames in DOS/Windows and Unix/Linux Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-09-03 22:18 +0000
                Re: Long filenames in DOS/Windows and Unix/Linux scott@slp53.sl.home (Scott Lurndal) - 2024-09-03 22:59 +0000
                Re: Long filenames in DOS/Windows and Unix/Linux Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-09-03 16:10 -0700
                Re: Long filenames in DOS/Windows and Unix/Linux Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-09-03 23:54 +0000
                Re: Long filenames in DOS/Windows and Unix/Linux Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-09-03 17:27 -0700
                Re: Long filenames in DOS/Windows and Unix/Linux Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-09-04 00:44 +0000
                Re: Long filenames in DOS/Windows and Unix/Linux Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-09-03 21:36 -0700
                Re: Long filenames in DOS/Windows and Unix/Linux Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-09-04 07:05 +0000
                Re: Long filenames in DOS/Windows and Unix/Linux Ralf Fassel <ralfixx@gmx.de> - 2024-09-04 11:47 +0200
                Re: Long filenames in DOS/Windows and Unix/Linux Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-09-04 03:44 -0700
                Re: Long filenames in DOS/Windows and Unix/Linux Nuno Silva <nunojsilva@invalid.invalid> - 2024-09-04 13:33 +0100
                Always use "--" (Was: Long filenames in DOS/Windows and Unix/Linux) gazelle@shell.xmission.com (Kenny McCormack) - 2024-09-04 13:04 +0000
                Re: Always use "--" (Was: Long filenames in DOS/Windows and Unix/Linux) Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2024-09-04 13:17 +0000
                Re: Always use "--" (Was: Long filenames in DOS/Windows and Unix/Linux) Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-09-04 21:35 +0000
                Re: Always use "--" (Was: Long filenames in DOS/Windows and Unix/Linux) Kaz Kylheku <643-408-1753@kylheku.com> - 2024-09-05 02:29 +0000
                Re: Always use "--" (Was: Long filenames in DOS/Windows and Unix/Linux) Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2024-09-05 14:48 +0000
                Re: Long filenames in DOS/Windows and Unix/Linux Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-03 17:35 -0700
                Re: Long filenames in DOS/Windows and Unix/Linux Kaz Kylheku <643-408-1753@kylheku.com> - 2024-09-03 23:15 +0000
                Re: Long filenames in DOS/Windows and Unix/Linux Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-09-03 16:38 -0700
                Re: Long filenames in DOS/Windows and Unix/Linux Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-09-03 23:56 +0000
                Re: Long filenames in DOS/Windows and Unix/Linux Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-09-03 17:19 -0700
                Re: Long filenames in DOS/Windows and Unix/Linux Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-09-04 00:41 +0000
                Re: Long filenames in DOS/Windows and Unix/Linux Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-09-03 21:29 -0700
                Re: Long filenames in DOS/Windows and Unix/Linux Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-09-04 06:49 +0000
                Re: Long filenames in DOS/Windows and Unix/Linux Nuno Silva <nunojsilva@invalid.invalid> - 2024-09-04 10:16 +0100
                Re: Long filenames in DOS/Windows and Unix/Linux Kaz Kylheku <643-408-1753@kylheku.com> - 2024-09-04 14:30 +0000
                Re: Long filenames in DOS/Windows and Unix/Linux John Ames <commodorejohn@gmail.com> - 2024-09-04 08:41 -0700
                Re: Long filenames in DOS/Windows and Unix/Linux Muttley@dastardlyhq.com - 2024-09-04 15:57 +0000
                Re: Long filenames in DOS/Windows and Unix/Linux Richard Kettlewell <invalid@invalid.invalid> - 2024-09-04 18:03 +0100
                Re: Long filenames in DOS/Windows and Unix/Linux Ralf Fassel <ralfixx@gmx.de> - 2024-09-05 11:29 +0200
                Re: Long filenames in DOS/Windows and Unix/Linux Richard Kettlewell <invalid@invalid.invalid> - 2024-09-05 18:21 +0100
                Re: Long filenames in DOS/Windows and Unix/Linux candycanearter07 <candycanearter07@candycanearter07.nomail.afraid> - 2024-09-07 18:20 +0000
                Word splitting oddities (Was: Long filenames in DOS/Windows and Unix/Linux) gazelle@shell.xmission.com (Kenny McCormack) - 2024-09-07 21:51 +0000
                Re: Long filenames in DOS/Windows and Unix/Linux Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-09-10 07:17 +0200
          Re: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to stdin) Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-09-10 06:51 +0200
      Re: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to Muttley@dastardlyhq.com - 2024-09-04 07:31 +0000
  Re: Long filenames in DOS/Windows and Unix/Linux (Was: Piping to stdin) Marcel Mueller <news.5.maazl@spamgourmet.org> - 2024-09-01 11:44 +0200

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