B-shell .logout - thanks and next question

[jc at cdx39.UUCP]

First, many thanks for all the people who answered my question
("How do you get a Bourne shell to run a .logout script?").  It
looks like the right answer involves the 'trap' command.  However,
the manual entry doesn't quite give the whole story.

I had tried using 'trap', and was under the (perhaps mistaken) 
impression that it didn't work very well.  Various respondents
said that they've been using it and been happy with the results.

One of the responses gave me a hint as to what the problem might 
be:  ...!ptsfa!jmc [hmm...those are my initials; I wonder what 
the real name is] warned me that some commands like chgrp do some 
unspecified funny things to traps.

A little experimenting verified that this is indeed true.  If
I do a chgrp, there seem to be funny changes to the trap setup
that I don't quite grok.  So, rather than beat my head against
that particular wall, I thought I'd toss this one out to our
pool of experts.

What really gives with the B-shell's trap mechanism?  Can anyone
post a list of commands that subvert a trap setup? Is there a 
straightforward way to run things like chgrp and leave the trap 
setup unaltered?  Am I a hopeless dreamer?

Does this perhaps belong in comp.unix.wizards?  [Yah, probably.]

-- 
	John M Chambers			Phone: 617/364-2000x7304
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