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From: chet.ramey@case.edu (Chet Ramey)
Subject: [TUHS] /bin/true (was basic tools / Universal Unix)
Date: Fri, 20 Oct 2017 08:10:03 -0400	[thread overview]
Message-ID: <9b4e27d3-afe4-902b-1650-bc85518f3f60@case.edu> (raw)
In-Reply-To: <alpine.BSF.2.21.1710200959200.30357@aneurin.horsfall.org>

On 10/19/17 7:00 PM, Dave Horsfall wrote:
> On Thu, 19 Oct 2017, Chet Ramey wrote:
> 
>> Yes, Posix requires that all builtins be execable. It doesn't require
>> true and false to be implemented as builtins, though.
> 
> Good luck with "cd"...

It doesn't have to do what you think it should. Using `cd' with something
like `find' or `env' is a fine way to test directory accessibility. The
Posix standard contains several examples of such use.

http://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xcu_chap01.html#tag_23_01_07
-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
		 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet at case.edu    http://cnswww.cns.cwru.edu/~chet/


  parent reply	other threads:[~2017-10-20 12:10 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-19 14:52 /bin/true (was [TUHS] " Ron Natalie
2017-10-19 15:01 ` Pete Wright
2017-10-19 15:17   ` Chet Ramey
2017-10-19 21:23 ` Steffen Nurpmeso
2017-10-19 21:43   ` Chet Ramey
2017-10-19 23:00     ` [TUHS] /bin/true (was " Dave Horsfall
2017-10-19 23:14       ` Grant Taylor
2017-10-19 23:23         ` Lyndon Nerenberg
2017-10-19 23:27         ` Kurt H Maier
2017-10-22  4:18           ` Dave Horsfall
2017-10-20 12:10       ` Chet Ramey [this message]
2017-10-19 21:43 ` /bin/true (was [TUHS] " Dave Horsfall
2017-10-19 22:04   ` Ronald Natalie
2017-10-19 23:25     ` [TUHS] /bin/true (was " Dave Horsfall
     [not found] ` <CAEoi9W7YZ7YXUip0JTMGip3Nd0czgdjqRCMRcK2GYmDJsckuDg@mail.gmail.com>
     [not found]   ` <CAEoi9W4zdJ3+RXjK5-5rAJ6rwx_0kx6N-bn1U61=txJGyLT_mw@mail.gmail.com>
2017-10-20  1:27     ` Dan Cross
2017-10-20  1:31       ` Lyndon Nerenberg
2017-10-20  2:05         ` Ronald Natalie
2017-11-28 16:21 ` Nemo
2017-11-28 17:56   ` Warner Losh
2017-11-28 18:26     ` Dan Cross
2017-11-28 18:41       ` Warner Losh
2017-11-28 19:09         ` Dan Cross
2017-11-28 20:34           ` Clem Cole
2017-11-28 22:42           ` Ralph Corderoy
2017-11-28 18:34     ` Bakul Shah
2017-11-28 23:25     ` Ralph Corderoy
2017-10-22 23:00 Doug McIlroy
2017-10-23  1:11 ` Dan Cross

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