t_client.sh: Add support for Kerberos/ksu

t_client.sh: Add support for Kerberos/ksu

If the t_client.rc have PREFER_KSU=1 configured, t_client.sh
will check if you have a valid Kerberos ticket and if so it will
do all execution via ksu instead of sudo.

If PREFER_KSU is not set or a Kerberos ticket is not found, it
will fallback to the configured RUN_SUDO approach.

When using ksu it needs the full path to the program being executed,
so there is also additional code to find the full path of true and kill.

[ v2 - Remove $* from RUN_SUDO for ksu config.  Old cruft which survived
       last review before patch submission.
     - Improve known state declaration of PREFER_KSU ]

[ v3 - Kick out bashism - '&>' redirect ]

Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <1474109433-4710-1-git-send-email-davids@openvpn.net>
URL: http://www.mail-archive.com/search?l=mid&q=1474109433-4710-1-git-send-email-davids@openvpn.net
Signed-off-by: Gert Doering <gert@greenie.muc.de>