Date: Fri, 25 Jan 2019 08:28:51 +0000 From: Edward Napierala <trasz@freebsd.org> To: Devin Teske <dteske@freebsd.org> Cc: rgrimes@freebsd.org, src-committers <src-committers@freebsd.org>, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r343440 - head/bin/sh Message-ID: <20190125082851.GA26199@v2> In-Reply-To: <D7EEA6BA-EAA6-4A84-A7C4-904999B0E581@FreeBSD.org> References: <201901251709.x0PH9Rc4094379@repo.freebsd.org> <201901251957.x0PJvdTL089917@pdx.rh.CN85.dnsmgr.net> <CAFLM3-oSafSxcWSJPEXQ8szLEq5N593fr=sEsup6A2%2BP_VXrgQ@mail.gmail.com> <D7EEA6BA-EAA6-4A84-A7C4-904999B0E581@FreeBSD.org>
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On 0125T1441, Devin Teske wrote: > > > > On Jan 25, 2019, at 1:37 PM, Edward Napierala <trasz@freebsd.org> wrote: > > > > pt., 25 sty 2019 o 19:57 Rodney W. Grimes > > <freebsd@pdx.rh.cn85.dnsmgr.net <mailto:freebsd@pdx.rh.cn85.dnsmgr.net>> napisał(a): > >> > >>> Author: trasz > >>> Date: Fri Jan 25 17:09:26 2019 > >>> New Revision: 343440 > >>> URL: https://svnweb.freebsd.org/changeset/base/343440 > >>> > >>> Log: > >>> Comment out the default sh(1) aliases for root, introduced in r343416. > >>> The rest of this stuff is still to be discussed, but I think at this > >>> point we have the agreement that the aliases should go. > >>> > >>> MFC after: 2 weeks > >>> Sponsored by: DARPA, AFRL > >> > >> Please just revert this and the prior commit out, and when > >> the path forward is clear commit it. I would not want any of this > >> merged to 12/ or 11/ until the time that it is all settled. > > > > Oops, my bad - neither this nor the previous commit is supposed > > to be MFC-ed; the "2 weeks" above comes from my default Subversion > > config. > > > > Regarding the backoff - just a few hours ago you said you don't have > > any problem with this, except for aliases and the default ENV. The > > aliases problem has been addressed, and you hadn't yet responded > > to my explanations regarding the ENV. Another committer asked for > > backoff, because "sh is not an interactive shell", while in fact sh(1) > > is FreeBSD's default interactive shell except for root. Finally, there's > > one person who asked for revert, but without giving any reasons > > whatsoever. > > > > So far nobody had proposed any scenario where this would break > > anything, or even affect existing users. It seems like a typical bikeshed > > situation. > > It is not clear to me after reading r343416 and D18872 what this change is trying to solve. The idea is to make it easy to replace the default root shell - which many people consider broken, due to not supporting basic shell syntax - with something that actually works. > PS1 should have a reasonable default. If that default is not reasonable, then we should change the C code. > > Maybe I see things differently, but I'd rather see PS1 default change so no profile/shrc change is necessary. Thank you, that's actually a valid argument. I believe that's also what bash does. It would be more intrusive, though, and I kind of don't like the idea of hardcoding things that can easily be dealt with with in a more "high-level" way. > I prefer that sh, in its default configuration, not attempt to read $HOME/.shrc, for security reasons. Can you elaborate? It already reads $HOME/.profile; how is $HOME/.shrc different? > Further, it is documented that the contents of ENV may be ignored in privileged mode, negating these changes. True - so if someone finds the idea of having a suid shell useful - from what I undestand that's what the privileged mode boils down to - this change will be a no-op. I seriously hope nobody does, though. > If you wanted your new shiny default PS1 to actually have an effect in all modes (including privileged mode, where you probably want it), you would have put it in /etc/profile and not in a file that is wholly ignored by some modes (e.g., privileged mode). > So the solution is not even the right one for the desired result. I would, if only it didn't break zsh, and perhaps others. The problem here is that zsh uses different syntax for PS1, _and_ it also parses /etc/profile. And no, I don't care at all about privileged mode, I can't imagine a situation when using it would be a good idea.
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