Re: Scripts in the '/etc/profile.d/' directory

On Wed, 2025-09-24 at 03:04 -0300, Jamenson Espindula wrote:
> Em ter., 23 de set. de 2025 às 23:46, Xi Ruoyao
> <[email protected]> escreveu:
> > 
> > How can they instantiate a GNU Screen without login first?
> > 
> > Basically /etc/profile.d/* should only export environment variables
> > and
> > whenever you start a shell in a login session, it should inherit
> > the
> > environment variables already exported.  If some "essential
> > configuration" is not an exported environment variable, or the
> > environment variable shouldn't be inherited (like the GPG_TTY one),
> > it
> > just shouldn't be in /etc/profile.d (it should be in bashrc
> > instead).
> > 
> > Yes the approach will fail if the login shell is not bash (I use
> > zsh),
> > or you somehow start GNU Screen via initscript or systemd unit, but
> > I
> > think those things are currently completely unsupported by the
> > book.  If
> > you do those you are on your own (like I).
> > 
> > --
> > Xi Ruoyao <[email protected]>
> > --
> > http://lists.linuxfromscratch.org/sympa/info/blfs-dev
> > Unsubscribe: See the above information page
> 
> More context to help understand what I mean.
> 
> I use the GNU Bash, as recommended in the LFS and BLFS books. I
> always
> build the packages manually (only one time I built the LFS system via
> jhalfs). However, I use GNU Screen to copy the build commands from
> the
> books and paste them in the command line (typing all the build
> commands is highly error prone and time consuming).
> 
> That said, I realized that, inside the GNU Screen, neither completion
> of the GNU Bash was working, nor the 'Xorg Build Environment'. The
> completion is not so 'essential', but the 'Xorg Build Environment' is
> highly 'essential' to whoever is going to build the X Window System!
> 
> I am building my new LFS. I have been aware of that all for a long
> time now, but never posted a word about it before. I understand that
> you, LFS Developer Team, deserves to be aware that, inside the GNU
> Screen, neither the completions of the GNU Bash will work nor the
> 'Xorg Build Environment' will be configured (considering the default
> configurations and the stock files).
> 
> I hope that adition helped clear the initial post!

According to "man bash", /etc/profile is only for login shells, and
users may expect this to be true. So adding automated ways to read this
in non-login shells would defeat normal bash expectations. I don't
think the book should propose this.

But of course, users may do what they want: for example, jhalfs is
faced to the same problem, and has "source /etc/profile" in all its
scripts. This has the advantage of immediately updating the environment
when some script changes the content of files in /etc/profiles.d.

There are several solutions for your use case, I think. One is to have
a dedicated user for building packages and have "source /etc/profile"
in its ~/.bashrc, and use another user when you want the normal bash
behavior.

Pierre

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