From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 In-Reply-To: References: From: Dan Cross Date: Tue, 17 Oct 2017 10:39:28 -0400 Message-ID: To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Type: text/plain; charset="UTF-8" Subject: Re: [9fans] Why Plan 9 uses $ifs instead of $IFS? Topicbox-Message-UUID: c30ce3f6-ead9-11e9-9d60-3106f5b1d025 On Tue, Oct 17, 2017 at 10:38 AM, Giacomo Tesio 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.