tcsh problem on 2.0.1

[Ron Flax]

In article <989 at lychee.cs.utexas.edu> ckwang at cs.utexas.edu (Chih-kan Wang) writes:
>I downloaded the compiled tcsh from aux.support.apple.com, put it in /bin,
>edited the /etc/shells, set proper access mode (as the root), and chsh to
>tcsh (in an ordinary user account). Then when I login again and opened
>commandshells, my .login file in home directory didn't get executed. But
>if I changed back to csh, everything went back to normal.  Does anybody
>have any similar experience?
>
>The configuration is:

>	tcsh 5.18 compiled for AUX 2.0

Well for starters you should probably grab version 5.20.02 from
afsg.apple.com at 192.1.34.2.

Here's what is going on.. tcsh determines that it is a "login shell" by
looking at it's own argc and argv upon execution.  

	if (argc==1 && *argv[0] == '-')
		tcsh is a login shell;
	else
		tcsh is NOT a login shell;

If tcsh thinks it's a login shell, it processes /etc/csh.login, .tcshrc,
.login, .cshrc, .logout, and /etc/Logout.  If it's not a login shell
then it only processes .tcshrc and .cshrc.

That said, here's what is happening... /mac/bin/Login calls tcsh as
follows to start your mac environment:

	-tcsh -c /mac/bin/mac32

You can see it sets up *argv[0] ok, but argc=3, not 1.  So it's not
considered a login shell and therefore doesn't process the apropriate
dot files.

Now let's say you login to the Console Emulator screen instead of a
32-bit Macintosh environment.  Here's what /mac/bin/Login does:

	-tcsh

Now both requirements are satisfied, and tcsh thinks it's a login
shell.

To fix things so that tcsh will process your .login file you can trick
the shell by creating a .tcshrc file and placing a line that reads:

	source ~/.login

in that file. This will force tcsh to process your .login file.  You can
even get a little more specific and only have that occur if the tcsh
process is connected to the console.  For instance you could do the
following:

	if ( `/bin/tty` == /dev/console ) source ~/.login

Hope this helps you to understand how tcsh is handling startup files.

--
Ron Flax
ron at afsg.apple.com	
Apple Federal Systems Group