:autocmd BufWritePost * !cat <afile> | nc remotehost 4242

Beaucoup d’autres possibilité existent.

Sources :

http://stackoverflow.com/questions/4627701/vim-how-to-execute-automatically-execute-a-shell-command-after-saving-a-file

http://stackoverflow.com/questions/601039/vim-save-and-run-at-the-same-time