Hello BLFS Development! It's been a while since my first post here, so I figured I would add some of my observations since 6.2 has been released. I'll only be discussing the section "The Bash Shell Startup Files" today, since it is still fresh in my mind from my most recent build.
First, a quick bug in the book: tinker_term.sh is still referenced in the sample /etc/bashrc, which may be confusing to newcomers. The ticket is here: http://wiki.linuxfromscratch.org/blfs/ticket/2314#preview But the main reason I'm posting to the mailing list today is to discuss the way the scripts set the environment variable PATH. As is standard convention, it is done through /etc/profile, but there are a few flaws that I have come to realize relating to using something as simple as su. When I'm installing packages, I tend to use su constantly so that I can switch in and out of root access to the filesystem. I'm sure lots of you do this. Others among you, notably the jhalfs developers, might make more use of sudo. I don't use sudo so I don't know how this affects it. In BLFS, there is no mention of /etc/login.defs. On a default lfs system, login.defs provides a basic PATH for users and root. When su is used, it draws your PATH from this file, completely avoiding /etc/profile.d/extrapaths.sh. Of course, this isn't the case when you use 'su -', since it then parses the profile of the user, although this is not the way people tend to call su when installing packages - it's not ideal to have to cd back to where you were. With that said, what is the problem? By default, /usr/local is completely ignored. This is because it is only configured in /etc/profile.d/extrapaths.sh, and since su is gathering it's PATH information from /etc/login.defs it gets the standard default of PATH=/sbin:/bin:/usr/sbin:/usr/bin. The same semantics caused a simular bug with umask. My user (jonathan, group jonathan) got the default umask of 002 because of his uid being equal to gid. After compiling gpm and su-ing, I installed gpm user and group read-writable as root:root. Why? Because umask settings are controlled through /etc/profile, and su ignores it. The first fix I want to suggest breaks standard convention. The only way I see this consistantly working without running scripts multiple times would be to set PATH with /etc/bashrc instead of /etc/profile, and remove the settings from /etc/login.defs all together. This would provide root, no matter how you logged in, with the intended default PATH. The other fix method would be to set the PATH in /etc/login.defs as well, but I personally hate having multiple definitions throughout a system for the same thing - it's just harder to maintain. Plus, there might be a problem with this method if you use PAM. On my BLFS-6.1 system the PATH settings in login.defs are completely ignored when I use PAM, though that may be my specific configuration as I'm no longer using the defaults from the book. I have yet to install PAM on BLFS-6.2 so I could be wrong, but currently I consider this method with PAM unreliable. I don't like the fixes that I'm suggesting, but I also don't like this behavior, and I personally consider this to be a bug. I also don't see any other ways to fix it. Any thoughts? Jonathan -- http://linuxfromscratch.org/mailman/listinfo/blfs-dev FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page
