cutucando POSIX :
Initialization in ex and vi
See Initialization in ex and vi for a description of ex and vi
initialization for the vi utility.
E a página de manual para ex
diz:
IEEE Std 1003.1-2001 does not mention system-wide ex and vi start-up
files. While they exist in several implementations of ex and vi, they
are not present in any implementations considered historical practice
by IEEE Std 1003.1-2001. Implementations that have such files should
use them only if they are owned by the real user ID or an appropriate
user (for example, root on UNIX systems) and if they are not writable
by any user other than their owner. System-wide start-up files should
be read before the EXINIT variable, $HOME/.exrc, or local .exrc files
are evaluated.
Então eu suponho que /etc/exrc
é sua melhor aposta para a velha escola vi
.
No entanto, vi
no CentOS 7 provavelmente é apenas vim-minimal
e, nesse caso, os arquivos de inicialização ainda usarão vim
em seu nome: /etc/vimrc
ou /etc/vim/vimrc
.