The Unix Heritage Society mailing list
 help / color / mirror / Atom feed
From: dave@horsfall.org (Dave Horsfall)
Subject: [TUHS] Shell control through external commands
Date: Fri, 15 Jul 2016 11:04:45 +1000 (EST)	[thread overview]
Message-ID: <alpine.BSF.2.11.1607151050240.65801@aneurin.horsfall.org> (raw)
In-Reply-To: <CAH_OBidB9EsULxX1+nY=Mg4SJ20OqCa+6eBk2KOPU-S_81hihw@mail.gmail.com>

On Thu, 14 Jul 2016, shawn wilson wrote:

> I've always been curious though - what was the reason behind 
> implementing /bin/[ ? IDK any shell where this isn't implemented - I 
> always assumed it's a POSIX compatibility stopgap older systems needed 
> to stay compliant with their shipped shell.

To implement:

    [ blah ]

when it wasn't a built-in (there were few built-ins in those days).

I have no idea why it's still there...  A Posix requirement, along with 
really unsafe functions?

By the way, on both Mac and FreeBSD (I can't be bothered checking my
Penguin box) "true" and "false" are binaries (and aren't even linked).

-- 
Dave Horsfall DTM (VK2KFU)  "Those who don't understand security will suffer."


  reply	other threads:[~2016-07-15  1:04 UTC|newest]

Thread overview: 69+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-14 13:18 Diomidis Spinellis
2016-07-14 13:23 ` Clem Cole
2016-07-14 14:12   ` Mary Ann Horton
2016-07-14 22:36   ` Dave Horsfall
2016-07-14 22:47     ` Corey Lindsly
2016-07-14 22:49     ` Peter Jeremy
2016-07-14 23:27       ` Marc Rochkind
2016-07-15 10:13         ` Joerg Schilling
     [not found]       ` <CAH_OBieVFzPn93L8=_fmbUycZ7UmYdXiopC0vgei6RGDZp0mHw@mail.gmail.com>
     [not found]         ` <CAH_OBie_6gFy+BqkCMj+sr0NqTMNOQxvgWf6SQnHMJpn7DAytA@mail.gmail.com>
2016-07-14 23:56           ` shawn wilson
2016-07-15  1:04             ` Dave Horsfall [this message]
2016-07-15  1:22               ` Steve Nickolas
2016-07-15  2:25               ` arnold
2016-07-16  6:26                 ` Dave Horsfall
2016-07-15  2:25             ` Random832
2016-07-15  3:59               ` Dave Horsfall
2016-07-15  4:09                 ` Random832
2016-07-15 13:55                 ` Chet Ramey
2016-07-14 23:10     ` Ronald Natalie
2016-07-15  1:41       ` Nemo
2016-07-15  9:00     ` Tony Finch
2016-07-14 14:11 ` schoedel
2016-07-14 14:38   ` Diomidis Spinellis
2016-07-14 15:46 ` John Cowan
2016-07-14 16:30   ` Random832
2016-07-14 22:32 ` Dave Horsfall
2016-07-15  4:29 Rudi Blom
2016-07-15 12:27 Norman Wilson
2016-09-10  7:45 ` Dario Niedermann
2016-09-10  9:13   ` Michael Kjörling
2016-09-10  9:41     ` Joerg Schilling
2016-09-10 17:06     ` Random832
2016-09-10 17:45       ` Dario Niedermann
2016-09-10 19:53         ` Dan Cross
2016-09-10 20:02         ` Chet Ramey
2016-09-10 20:27           ` Dario Niedermann
2016-09-11 10:03         ` Diomidis Spinellis
2016-09-12 10:05         ` Jacob Goense
2016-07-15 16:47 Doug McIlroy
2016-09-10 17:40 ` Dario Niedermann
2016-09-10 19:22   ` arnold
2016-09-12  8:35     ` markus schnalke
2016-09-12  9:25       ` Joerg Schilling
2016-09-12 12:41         ` Tony Finch
2016-09-12 12:50           ` Joerg Schilling
2016-09-13  0:17             ` Sven Mascheck
2016-09-13  1:45               ` Sven Mascheck
2016-09-13  9:20               ` Joerg Schilling
2016-09-12 20:12       ` Dave Horsfall
2016-09-12 21:36         ` Dave Horsfall
2016-09-10 22:43   ` Dave Horsfall
2016-09-11  1:24     ` Ron Natalie
2016-09-11  2:39       ` arnold
2016-09-11  2:41         ` Ronald Natalie
2016-09-11  4:07         ` Dave Horsfall
2016-09-11  5:01           ` arnold
2016-09-12  5:49             ` Dave Horsfall
2016-09-10 14:57 Nemo
2016-09-11 17:39 Doug McIlroy
2016-09-11 18:11 ` Clem Cole
2016-09-11 18:27 ` Dan Cross
2016-09-11 18:50   ` Sven Mascheck
2016-09-11 22:13     ` Random832
2016-09-12  0:27 Doug McIlroy
2016-09-12  1:31 Norman Wilson
2016-09-12  9:33 ` Joerg Schilling
2016-09-12  1:43 Norman Wilson
2016-09-12  9:18 ` Joerg Schilling
2016-09-12 12:56 Norman Wilson
2016-09-12 12:57 Norman Wilson

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=alpine.BSF.2.11.1607151050240.65801@aneurin.horsfall.org \
    --to=dave@horsfall.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).