how to use the -t option in csh

[Guy Harris]

>What is the purpose of the -t option in csh and 
>how does one use it.

Mr. Kamens' explanation of how to use it, and why you probably don't
want to use it, is correct.

I assume the purpose for it is the same as the purpose for "-t" flags in
other shells, dating back to the V6 shell, which is that it's there for
the benefit of "ed"'s "!" command.

The V6 "ed" used "read()" to read its command line one character at a
time.  If it discovered that the character was a "!", as I remember it
would then fire off a shell with the "-t" flag, and that shell would
then read the rest of the line.  I forget whether the original V6 shell
(we're talking V6, an OS that came out in 1975, folks...) even had a
"-c" flag.

I don't think many programs bother using the "-t" flag any more; they
tend to use "-c" instead.