See the UNIX Programmers Manual or via % man csh
% setenv
EXINIT 'set autoindent shell=/bin/csh'
The environment variable EXINIT is set to the string in single quotes.
This variable is used by the editors, ed, ex, edit, and vi, for
initialization. In this case the editor variables named 'autoindent' and
'shell' are set. To see these in the editor, use
:set all
% setenv TERMCAP /kemp/TERMCAP
will cause the TERMCAP string to become that specified in /kemp/TERMCAP.
This allows you to customize a termcap terminal definition.