From: Dan Cross <crossd@gmail.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Subject: Re: [9fans] Why Plan 9 uses $ifs instead of $IFS?
Date: Tue, 17 Oct 2017 10:39:28 -0400 [thread overview]
Message-ID: <CAEoi9W4qdU_rk2HuPtWh+9vfYy33C9vS5JD-YSffkvWA6djdBg@mail.gmail.com> (raw)
In-Reply-To: <CAHL7psFQ7P83jF1GSuatRRV4_a+YuphMzwuGMTx=pTscpGLJtg@mail.gmail.com>
On Tue, Oct 17, 2017 at 10:38 AM, Giacomo Tesio <giacomo@tesio.it> wrote:
> Out of curiosity, do anybody know why Plan9 designers chose lowercase
> variables over uppercase ones?
>
> At first, given the different conventions between rc and sh (eg $path is an
> array, while $PATH is a string), I supposed Plan 9 designers wanted to
> prevent conflict with unix tools relying to the older conventions.
>
> However, I'm not sure this was the main reason, as this also open to subtle
> issues: if a unix shell modifies $IFS and then invoke an rc script, such
> script will ignore the change and keep using the previous $ifs.
>
>
> As far as I can see, APE does not attempt any translation between the two
> conventions, so maybe I'm just missing something obvious...
>
>
> Do anyone know what considerations led to such design decision?
Aesthetics.
next prev parent reply other threads:[~2017-10-17 14:39 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-17 14:38 Giacomo Tesio
2017-10-17 14:39 ` Dan Cross [this message]
2017-10-17 15:05 ` Giacomo Tesio
2017-10-17 15:18 ` Charles Forsyth
2017-10-17 15:45 ` Giacomo Tesio
2017-10-17 16:04 ` Giacomo Tesio
2017-10-17 17:35 ` Dan Cross
2017-10-17 22:32 ` Tiago Natel
2017-10-17 16:00 ` Skip Tavakkolian
2017-10-17 16:22 ` Giacomo Tesio
2017-10-17 15:46 ` Teodoro Santoni
2017-10-17 18:28 ` Anthony Martin
2017-10-17 21:12 ` Jules Merit
2017-10-17 21:45 ` Jules Merit
2017-10-17 21:49 ` Jules Merit
2017-10-17 22:18 ` Charles Forsyth
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=CAEoi9W4qdU_rk2HuPtWh+9vfYy33C9vS5JD-YSffkvWA6djdBg@mail.gmail.com \
--to=crossd@gmail.com \
--cc=9fans@9fans.net \
/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).