On Thu, May 31, 2018 at 09:01:49AM +0200, Ævar Arnfjörð Bjarmason wrote: > > Is there some case where a pager can only handle color if _it's_ output > > is going to a tty, and otherwise not? > > Maybe I'm missing something but how is that something we can deal with? > We just: > > 1. use isatty() to see if we're attached to a terminal > 2a. If yes and no pager is invoked (e.g. git status) and "auto" we use colors > 2b. If yes and we're invoking a pager (e.g. git log) and "auto" we use colors > 3b. At this point we're writing to the pager so isatty() is false, > but we set our own GIT_PAGER_IN_USE and turn on colors if "auto" > > I suppose we can imagine a pager that sometimes emits to a terminal and > sometimes e.g. opens a browser with the output, and we could ourselves > somehow detect this... I was imagining something where we remembered the original isatty() value (from before the pager) and then reacted to that. But no, I don't actually have a use case there. I was trying to think through possible reasons to want this "isatty" version of color.ui. > As noted in the cover letter I started writing this whole thing before > understanding some of the subtleties, and now I think this "isatty" > thing is probably pretty useless, and was wondering if others wanted it. OK, I agree that it doesn't seem all that useful. > Reasons to take it are: > > 1) To make user intent clearer. I.e. we could just also make it a > synonym for color.ui=auto & color.pager=false and those used to > isatty semantics skimming the docs would more easily find the right > thing. I'd much prefer just having a documentation patch that uses the word "isatty", if that's something we think a user might search for (which seems plausible to me). > 2) If there are any cases where isatty() is true, but we can detect via > other means (e.g. inspecting other env variables) that non-pager > output can't handle colors some of the time. Of course if we find > such cases isatty() would suck more, but that's presumably what > isatty() purists want :) Yeah, I think we can punt on that until such an "other means" comes along. -Peff
