From: Chet Ramey <chet.ramey@case.edu>
To: Michael Siegel <msi@malbolge.net>
Cc: tuhs@minnie.tuhs.org
Subject: Re: [TUHS] Arithmetic expansion in Unix shells
Date: Mon, 21 Jun 2021 10:48:18 -0400 [thread overview]
Message-ID: <bf61298e-9f69-d091-1e6c-763e413f719b@case.edu> (raw)
In-Reply-To: <20210621164315.1587cffe@moon>
On 6/21/21 10:43 AM, Michael Siegel wrote:
> Am Mon, 21 Jun 2021 09:50:38 -0400
> schrieb Chet Ramey <chet.ramey@case.edu>:
>
>> The $((...)) form of arithmetic expansion is something POSIX picked up
>> from ksh-88, eventually. The early drafts of the standard (through
>> 1003.2 d9, at least), used $[...], but they eventually adopted
>> $((...)) because ksh-88 had already implemented it, though it's not
>> documented in Bolsky and Korn.
>
> So, in other words, POSIX shell (meaning the shell described in the
> standard as it has been released) had double-parentheses arithmetic
> evaluation from the start?
From the first published version of the standard, yes.
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU chet@case.edu http://tiswww.cwru.edu/~chet/
next prev parent reply other threads:[~2021-06-21 14:48 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-21 9:37 Michael Siegel
2021-06-21 9:57 ` arnold
2021-06-21 13:50 ` Chet Ramey
2021-06-21 14:43 ` Michael Siegel
2021-06-21 14:48 ` Chet Ramey [this message]
2021-06-22 16:24 ` Michael Siegel
2021-06-22 15:52 Brian Walden
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