I am trying to write a shell script that will construct a list of
words while inside a loop.  Here is the logic I would have expected to
work:

     #!/bin/sh
     LIST=""
     cat - | while true
     do
	 read WORD JUNK
	 if [ $? -ne 0 ]; then break; fi
	 LIST="$LIST $WORD"
	 echo "LIST:  $LIST"
     done
     echo "final LIST:  $LIST"

The problem is that the final value of $LIST is empty, though within
the loop the value grows as expected.  That is, the assignment inside
the loop seems to have no effect on the outermost $LIST.  Adding
export does not seem to matter.

I must be missing something obvious about shell variables.  How can
this be done?

Thanks for your help, and sorry for what must be something simple that
I'm completely missing.

Cheers,
Brook