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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.



  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

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