From: Phillip Wood Date: Wed, 23 Jun 2021 09:05:22 GMT Subject: Re: Forcing git to use a pager without a tty Message-ID: <077d147c-c22f-6463-6545-3aa991e7868b@gmail.com> In-Reply-To: Hi Avishay On 22/06/2021 23:40, Avishay Matayev wrote: > Hi there! > > Fugitive[1] is a vim plugin that wraps git and many of its commands > into the editor in a really awesome way, I won't meddle into it too > much as you can read about it in its README, but as you understand, it > uses git, a lot. > > Some git commands use a pager, which is usually a program that needs a > pty to function properly (`less`, for example). Fugitive can't really > use a pty for the pager as vim runs its subprocesses without a pty. > Therefore Fugitive just creates its own pager (which is a simple > window in vim) and pastes the git command output there. If I understand correctly fugitive is reading the output of the git command over a pipe and putting it into a vim buffer? > The only problem left is that Fugitive can't reliably know when git > decides to use the pager, for example `git reflog show` does raise the > pager while `git reflog expire` does not. Fugitive currently maintains > an (very possibly) incomplete list of commands that need a pager but > maintaining it manually isn't ideal. I don't understand, if as you say above there isn't a pty then git wont use a pager unless GIT_PAGER_IN_USE is set which Fugitive does not seem to, so I'm not sure what you mean by 'Fugitive can't reliably know when git decides to use the pager' > I started discussing this on an issue in Fugitive's github page[2] and > Tim Pope (the creator and maintainer of Fugitive, thank you!) > explained that `git` doesn't use a pager if there is no pty so it's > impossible to override its behavior. > > We had some ideas how to make this feasible (as you can read on the > thread) but for brevity's sake I'll present the best (IMO) idea: > Essentially, at `pager.c`, don't short-circuit in `git_pager` (or > `setup_pager`?) due to pty absence if a new environment variable is > present, perhaps something like `GIT_PAGER_FORCE` which will override > the `PAGER` and `GIT_PAGER` variables. This will allow Fugitive to > apply custom logic through to pager to know if one exists and present > the window in vim. I note that the latest comment [1] on the github issue talks about a different solution that would cause all git commands to behave as if there was a pty present. [1] https://github.com/tpope/vim-fugitive/issues/1772#issuecomment-866401942 Best Wishes Phillip > I will appreciate any written thoughts on the matter, thank you :) > > P.S. I am a complete newbie in regards to mailing lists etiquette, > pardon me if I've done anything incorrect > P.P.S. I CC'd Junio C Hamano because he signed off on (almost?) all > changes to `pager.c`, sorry if that was wrong of me (You probably got > this mail twice because of a misconfiguration, oops) > > > 1. https://github.com/tpope/vim-fugitive > 2. https://github.com/tpope/vim-fugitive/issues/1772 >