Re: csh to sh migration for root in RELENG_14

On Sat, 18 Nov 2023 02:07:24 -0700
"Edward Sanford Sutton, III" <mirror176@hotmail.com> wrote:

> On 11/17/23 12:41, Garrett Wollman wrote:
> > <<On Fri, 17 Nov 2023 13:40:44 -0500, mike tancsa <mike@sentex.net> said:
> > 
> >> I am trying to bring my environment along from previous versions where
> >> csh was the default shell and now trying to get used to sh. In the past
> >> things like
> > 
> >> sudo su
> > 
> >> would pick up my settings in /root/.cshrc automatically. However, with
> >> sh I have to do
> > 
> >> sudo su -l root
> > 
> >> Is there a way to configure it so I dont need the -l as part of the su
> >> to get the same behavior ?
> > 
> > See sh(1) section "Invocation", which describes how /bin/sh reads its
> > initialization files, and in particular, that (as POSIX specifies)
> > interactive non-login shells do not read any startup files unless the
> > environment variable `ENV` is set.  This is stupid but required by the
> > standard.
> > 
> > I would recommend changing root's shell to something that better suits
> > your needs: either change it back to csh, or install the appropriate
> > package and set it to bash or zsh, both of which read startup files
> > for all interactive shells, not just login shells.
> 
> Though it was worse when upgrading using portupgrade and less likely to 
> be an issue with packages, I would still consider trying to keep root's 
> shell as a shell that is part of base and if I really wanted a different 
> one then I would have a 3rd party shell get launched from a shell from 
> base as part of the sign in process so it could 'fall back' to skipping 
> the launch if it fails. This comes from having had issues with 3rd party 
> shells not functioning for reasons such as it depending on a library 
> that failed to install properly. I do not have my desktop boot into X 
> automatically or use a graphical login manager for the same reason; 
> problems are easier to fix when you can still log in successfully. I 
> have not often had such issues, but I certainly have had them.
> 
> > -GAWollman

Just a FYI:
I'm using zsh as interactive shell for now, and I have the line below
in ~/.tcshrc.mine, keeping base tcsh as login shell.

if ( -X zsh && -f ~/.Use_zsh ) exec zsh

This way, if zsh is executable in the path AND ~/.Use_zsh exists, zsh
is executed, otherwise tcsh keeps running as interactive shell.
If zsh accidentally (or intentionally) dissappears, base tcsh is used.
Assuming zsh is available and executable, I can intentionally create
~/.Use_zsh (`touch ~/.Use_zsh` is enough) to use zsh and delete it to
use base tcsh.

-- 
Tomoaki AOKI    <junchoon@dec.sakura.ne.jp>