Setting variables for a running process

[Peter Curran]

Here is a scheme for getting environment changes back to your "main"
shell (this works for /bin/sh.  I presume masochists could find
something similar in csh):

Add the following three lines to your .profile file:

trap '. $SHCMDS; rm -f $SHCMDS' 8
SHCMDS=$HOME/shcmds  SHPID=$$
export SHCMDS SHPID

Then, in suprocess, write shell commands into the file named in $SHCMDS,
and send signal 8 to the process identified by $SHPID.  For example,
in a shell script

echo "TERM=$TERM; export TERM" >$SHCMDS
signal -8 $SHPID

It is probably preferably that the '>' be '>>' to allow several
commands to be written out at once.  This will fail if you push
it too hard - the shell has to get time to execute the commands
before another command is issued.  However, it can be used for
all sorts of tricks.