How do I launch an editor from a shell script?

Question

I would like my tcsh script to launch an editor (e.g., vi, emacs):

#!/bin/tcsh
vi my_file

This starts up vi with my_file but first displays a w

Answer 1

The reason you're getting the error is that when you start a shell in your environment, it's starting in a subshell that has STDIN and STDOUT not connected to a TTY — probably because this is in something like a pipeline. When you redirect, you're opening a new connection directly to the device. So, for example, your command line turns

$ vi < `tty` > `tty`

into

$ vi < /dev/ttys000 > /dev/ttys000

So you're not really using your old STDIN/STDOUT, you're creating two new files and mapping them to your vi process's STDIN/STDOUT.

Now, tell us what you're doing with this and we'll tell you how to avoid this kludge.