From: Giacomo Tesio <giacomo@tesio.it>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Subject: [9fans] Why Plan 9 uses $ifs instead of $IFS?
Date: Tue, 17 Oct 2017 16:38:06 +0200 [thread overview]
Message-ID: <CAHL7psFQ7P83jF1GSuatRRV4_a+YuphMzwuGMTx=pTscpGLJtg@mail.gmail.com> (raw)
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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?
Giacomo
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next reply other threads:[~2017-10-17 14:38 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-17 14:38 Giacomo Tesio [this message]
2017-10-17 14:39 ` Dan Cross
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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