":" as a csh command

[David Elliott]

In article <666 at cullvax.UUCP> drw at cullvax.UUCP (Dale Worley) writes:
>What does the ':' command to csh do?  When I type
>	:
>or
>	::
>or
>	::::::
>csh doesn't seem to do anything, but if I type
>	: a
>it says ":: Too many arguments".
>

It helps you prevent running a shell script with csh. A file beginning
with

	: run this with sh, not csh

will fail immediately if run by csh.

You see, you can no longer reliably distinguish csh and sh scripts
by looking for '#' as the first character, since AT&T Unix systems
allow # as a comment and do not have csh scripts (it sure would
be nice if everyone spoke #!).

			David Elliott
			Mips Computer Systems