[sudo-users] why are my ~/.bashrc aliases not honoured by sudo ?

[Shriramana Sharma]

Hello I'm new to this list, and am only moderately knowledgeable 
technically, so please be patient my ignorance.

In both my /home/samjnaa/.bashrc and /root/.bashrc I have the alias rm = 
'rm -i' to prevent me from deleting stuff accidentally. (I can always 
use -f to override the -i if I'm really sure.) But I find that though 
both the user and root shells honour this alias, it is not honoured by 
sudo. See:

[samjnaa:~] cd /tmp
[samjnaa:/tmp] touch foo
[samjnaa:/tmp] rm foo
rm: remove regular empty file `foo'? n
[samjnaa:/tmp] sudo -i
[sudo] password for samjnaa:
[root:~] rm /tmp/foo
rm: remove regular empty file `/tmp/foo'? n
[root:~] exit
logout
[samjnaa:/tmp] sudo rm /tmp/foo
[samjnaa:/tmp]

Also with a sub-shell:

[samjnaa:/tmp] touch foo
[samjnaa:/tmp] sudo bash -c 'rm foo'
[samjnaa:/tmp]

I don't get it. IIRC sudo runs the command with the process's uid/gid=0. 
To execute the command, bash is needed anyhow. So whether bash reads the 
user's .bashrc or root's .bashrc, it must see and obey this alias. Why 
does this not happen? Does bash not see the rm command at all?

Thanks.

Shriramana Sharma.