From: Warner Losh <imp@bsdimp.com>
To: Anthony Martin <ality@pbrane.org>
Cc: The Eunuchs Hysterical Society <tuhs@tuhs.org>
Subject: Re: [TUHS] A question about ls(1)
Date: Sat, 27 Apr 2019 09:38:27 -0600 [thread overview]
Message-ID: <CANCZdfoftxQ47J7yu--Pqdgiatxz22axn=3Pq=8G30UQBAfpig@mail.gmail.com> (raw)
In-Reply-To: <20190427141655.GA8310@alice>
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On Sat, Apr 27, 2019 at 8:26 AM Anthony Martin <ality@pbrane.org> wrote:
> From at least V2 to V6, the ls(1) command would not
> show directory entries whose names began with a '.'
> unless the -a flag was supplied.
>
> This was changed in V7: only the directory entries
> for "." and ".." would be skipped by default.
>
gnu ls does not follow this convention. The system V sources one can find
on the internet have the curious code:
#define DOTSUP 1
...
if (aflg==0 && dentry->d_name[0]=='.'
# ifndef DOTSUP
&& (dentry->d_name[1]=='\0' ||
dentry->d_name[1]=='.'
&& dentry->d_name[2]=='\0')
# endif
) /* check for directory items '.', '..',
* and items without valid inode-number;
*/
continue;
which is the V7 behavior ifdef'd out.
> All further versions of Research Unix retain the
> convention of V7 and Plan 9 ultimately made it
> unnecessary. However, BSD and its descendants did
> not follow suit. Instead, they continued behaving
> like V6 with an additional -A flag to emulate V7.
>
This has been the BSD convention since at least 4BSD :)
But I find this interesting, since the 8th edition was based on BSD 4.1c I
thought....
And system III and later all have the above code.
> Was the initial behavior intentional or just a
> matter of expediency?
>
> Who made the change and what was their motivation?
> Was it a reaction to the intentional hiding of what
> came to be known as "dot files"?
It looks like, from the source, to be a blip in V7.
Warner
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next prev parent reply other threads:[~2019-04-27 15:39 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-27 14:16 Anthony Martin
2019-04-27 15:38 ` Warner Losh [this message]
2019-04-27 15:42 ` Larry McVoy
2019-04-28 23:59 ` Warner Losh
2019-04-28 11:47 ` Dan Cross
2019-04-28 12:00 ` arnold
2019-04-28 14:44 ` jcs
2019-04-28 16:15 ` Bakul Shah
2019-04-27 20:11 Norman Wilson
2019-04-27 23:03 Noel Chiappa
2019-04-28 16:54 Norman Wilson
2019-04-28 19:45 ` Jon Forrest
2019-04-28 20:00 ` Bakul Shah
2019-04-29 18:05 ` Michael Kjörling
2019-04-29 20:37 ` Warner Losh
2019-04-29 20:44 ` Christopher Browne
2019-04-30 6:44 ` Michael Kjörling
2019-04-30 7:24 ` Kurt H Maier
2019-04-30 10:35 ` Wesley Parish
2019-04-29 22:32 ` Bakul Shah
2019-04-30 11:52 ` Theodore Ts'o
2019-04-28 22:16 ` Thoma Paulsen
2019-04-29 0:53 ` John P. Linderman
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