Including <silent> will break this command:
nnoremap yn :!echo -n %c %i | xclip -in -selection clipboard<cr>
Is there any workaround for it? I tried system(), but can't get it to work.
I don't think that adding <silent> will affect the command, don't see how. This similar command works fine:
nnoremap <silent> yn :!echo -n %c > ~/file %i<cr>
You are right. I am not sure what was wrong before that wasn't working. Sorry about this.