Abstract

A summary of the way people have chosen to implement shell aliases for handling multiple sets of Kerberos tickets in the MIT Athena environment.

Overview

Around MIT Athena, most people who have cause to use multiple sets of Kerberos tickets within a given login session have a set of shell aliases for manipulating those ticket files. Since switching Kerberos tickets involves setting multiple environment variables (one each for Kerberos 4 and Kerberos 5), for practical use, these need to be implemented as shell aliases, rather than as shell scripts, etc.

For some reason, I've been lame for the past 6 years or so that this has mattered to me, and never really bothered to set up aliases, being mostly content to change ticket files by hand. Finally, though, a bunch of factors consipired to encourage me to do this properly.

I decided to write up an overview of what various notables around here use for aliases, and to do a comparison, as part of the process of deciding how best to implement this myself. That is this document.

Chosen users

An informed subset of the community was chosen. I looked at: Dan Winship <danw>, Greg Hudson <ghudson>, Jonathon Weiss <jweiss>, Marc Horowitz <marc>, Matt Braun <mhbraun>, Tom Yu <tlyu>, Yonah Schmeidler <yonah>, and Garry Zacheiss <zacheiss>>

Comparisons

User ModularSets Prompt ScoreObtains tickets
danw Yes No 1 Yes
ghudson Yes No 1 Both
jweiss No No 0 Yes
marc Yes No 1 No
mhbraun No Yes 1 No
tlyu No Yes 1 No
yonah Yes Yes 2 Yes
zacheissNo Yes 1 No

Definitions:

User
Who it was.
Modular
Is there code duplication for each alias, or is the alias structure modular enough to allow multiple aliases to reference a common "function."
Sets Prompt
Does it change the shell prompt?
Score
How many of the previous two?
Obtains tickets
Does the alias detect if you have obtained tickets and prompt you to get them? I don't know if this is a good idea.

I find it interesting that only ghudson and yonah bother to make their aliases fit in 80 columns.

tlyu's aliases don't handle Kerberos 5 (i.e. KRB5CCNAME), so perhaps they have not been udpated in some years, or I'm not looking at a current copy.

It also strikes me as odd that no one bothers to set the WGFILE environment variable, to reduce problems when using zephyr (either accidently, or through an attachandrun script).


Last modified on $Date: 2001/11/11 00:45:16 $ (UTC) by $Author: jhawk $.