Infrastructure Software

For a long time Solaris is supplied with the same default /etc/profile, with small variations (I attached the current one at the end of the message for reference). Recently, I investigated an issue related to setting up an user environment, had a close look at the /etc/profile, and found mistakes. Here they are.

/etc/profile:

1. Incorrectly assumes that login shell is always interactive. But login shell may also non-interactively execute some script.
   
   On script execution, displaying quota, motd and new mail notifications is inappropriate. Non-interactive login shell shall be as much verbose as `hushlogin' shell.
   
   
2. Irrelevantly guesses TERM.
   
   When gdm starts X-session
   

   /usr/sbin/gdm-binary
   `- /usr/lib/gdm-simple-slave
      `- /usr/lib/gdm-session-worker
         `- ...

   gdm-session-worker takes care to remove TERM (=sun-color) from session environment. But later, X startup scripts certainly source /etc/profile and resurrect console's TERM=sun-color into X environment. Then TERM=sun-color persists in the environment of each X session process. There is no much hurt from this, but this is ... ugly.
   
   IMO, guessing TERM is out of /etc/profile business. Why it's here?
3. Incorrectly assumes that login shell always has `-' in front of it's name. But this is not true, e.g.
   

   $ bash --login

   In this case the part of /etc/profile, enclosed in [case "$0" in -bash) ... esac] brackets, can not be reached, because `$0' is `bash'.
   
   
4. Incorrectly assumes that only login shell may source /etc/profile. But there is nothing wrong if anybody, due some reasons, reconstructs `login environment' in a separate, non-login shell, e.g.:
   

   $ env -i TERM=$TERM PATH=$PATH bash --norc
   bash-4.1$ . /etc/profile

   The part of /etc/profile, enclosed in [case "$0" in -bash) ... esac] brackets, shall be executed as for `normal' login, but it shall not, because `$0' is `bash'
   
   Here is a real life example. Look how X-session is been set up:
   

   /usr/sbin/gdm-binary
   `- /usr/lib/gdm-simple-slave
      `- /usr/lib/gdm-session-worker
         `- /bin/ksh /etc/gdm/Xsession gnome-session

   Then, in /etc/gdm/Xsession:
   

   32: # First read /etc/profile and .profile
   33: test -f /etc/profile && . /etc/profile
   34: test -f "$HOME/.profile" && . "$HOME/.profile"

   Again, the part of /etc/profile, enclosed in [case "$0" in -bash) ... esac] brackets, can not be reached, because `$0' is not even `bash', but `/etc/gdm/Xsession'.

The whole point of the items (3,4) is that :

detecting the exact kind of script interpreter by enumerating it's names [case "$0" in -sh | -ksh | -ksh93 | -jsh | -bash | -zsh)] does not work.

Why it's here?

Current (Solaris 11.3) /etc/profile, for reference:

# The profile that all logins get before using their own .profile.
trap ""  2 3
export LOGNAME PATH
if [ "$TERM" = "" ]
then
    if /bin/i386
    then
        TERM=sun-color
    else
        TERM=sun
    fi
    export TERM
fi
#    Login and -su shells get /etc/profile services.
#    -rsh is given its environment in its .profile.
case "$0" in
-sh | -ksh | -ksh93 | -jsh | -bash | -zsh)
    if [ ! -f .hushlogin ]
    then
        /usr/sbin/quota
        #    Allow the user to break the Message-Of-The-Day only.
        trap "trap '' 2"  2
        /bin/cat -s /etc/motd
        trap "" 2
        /bin/mail -E
        case $? in
        0) 
            echo "You have new mail."
              ;;
        2) 
            echo "You have mail."
               ;;
        esac
    fi
esac
umask 022
trap  2 3