On a stock CentOS 6.1 installation, if I start in my user shell (tcsh) with all my usual command aliases and do what I normally do (in other versions of Linux, and Mac OS X) to get a root shell,
my command aliases are not preserved. This is not the behavior I see with sudo on other operating systems, including older versions of RHEL (from which CentOS is derived). I've tried different variations in CentOS 6.1, such as
sudo -i tcsh sudo tcsh -m sudo -i tcsh -m
which by my reading of the sudo and tcsh man pages, should make it behave more like a login shell and presumably do things like interpret my .cshrc file, but nothing has worked. My default shell is /bin/tcsh in /etc/passwd; I've tried switching root's entry in /etc/passwd to also use /bin/tcsh (the default was /bin/bash), but it didn't make any difference.
I guess this behavior could be controlled by something in /etc/sudoers, but my /etc/sudoers is the stock file installed by CentOS 6.1, and comparing it to (e.g.) Mac OS X 10.6's /etc/sudoers file doesn't immediately reveal an obvious setting that would control this particular behavior.
I'm stumped at this point and would appreciate help.