From: usotsuki@buric.co (Steve Nickolas)
Subject: [TUHS] Shell control through external commands
Date: Thu, 14 Jul 2016 21:22:15 -0400 (EDT) [thread overview]
Message-ID: <alpine.BSF.2.02.1607142121420.90753@frieza.hoshinet.org> (raw)
In-Reply-To: <alpine.BSF.2.11.1607151050240.65801@aneurin.horsfall.org>
On Fri, 15 Jul 2016, Dave Horsfall wrote:
> 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).
>
>
$ file $(which true) $(which false)
/bin/true: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV),
dynamically linked (uses shared libs), for GNU/Linux 2.6.26,
BuildID[sha1]=0x347aaa1fa815d6689723e6f8aa0f7207566b6aba, stripped
/bin/false: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV),
dynamically linked (uses shared libs), for GNU/Linux 2.6.26,
BuildID[sha1]=0x821c6a0a4331413fb4b562b623c6bd5ca0a707f6, stripped
-uso.
next prev parent reply other threads:[~2016-07-15 1:22 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
2016-07-15 1:22 ` Steve Nickolas [this message]
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
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