Hello!

After adding a new user (through NIS server), when running "su new_user"
the current directory doesn't chanes to $HOME.
The shell in use is "tcsh" (for historical reasons: too much to rewrite for "bash"),
after "su new_user" running "echo $HOME" displays the correct $HOME directory,
running "cd" without arguments changes correctly to the $HOME directory.
Other, previously existing users also running "tcsh" have no such problem.
And, for the new user, the same problem exists on two different servers.
There is no ".login" file in our home directories.

I looked at the files /etc/csh.login and /etc/login.defs but didn't see there
anything that hints to the initial directory after login.

Any ideas, what causes "tcsh" to "cd" (or, in this case, not to "cd") to $HOME?

TIA,

Wouldn't that be with the -l option to start a login shell and have an environment like a normal login?

If you plan to migrate, despite Bash being the default, do take a look at Zsh, Fish, and Oil to see the current state of available shells. Myself, while I started out on tcsh, I quickly moved to Bash and have been there for ages. Lately I am even dabbling with Zsh.

Or the classic Unix
See the man page

Yes, I've read that adding the "-l" switch forces "login shell".
But why the same "su username" command behaves differently for old users and the new user?
I can live with

alias su 'su -l'

but I have a feeling that it's like sweeping the problem under the carpet: I still don't
understand the reason for same command behaving differently for different users.
Other users have no alias for "su" but somehow using this command without
the "-l" (or any other) switch it behaves like login shell.

TIA,
kaza.

Each tcsh runs the system /etc/csh.cshrc then the user's .tcshrc or .cshrc
A login tcsh additionally runs the system /etc/csh.login then the user's .login

If different users have different behavior with a plain su then look at their .tcshrc files if present otherwise their .cshrc files.