> I figured it out under fire...
That implies you could really -edit- a file using only /bin/sh and no other binaries.
All I can think is something like:
exec < file_to_be_editedor maybe instead of a single variable line, use a series of variables for each word parsed from the input on each line.... argggh. And you'd still have to use mv to rename it back, so that can't be right.
while read line; do
(some shell magic with line)
echo "$line" >> new_file
done
I'd love to know how; willin' to share?
You were right. Yes, you do need mv. I was typing in the answer, see the post above.