Saving Macros
let @q = 'macro contents'
Use "qp to paste contents of register, which is where the macro is stored.
Silent Write Visual Selected Lines
:silent! '<,'> w !command
If you want to use this in a nmap there is an issue: the : puts the cursor
after the :'<,'>:. The solution is this:
:vnoremap <silent> \c :w !cmd<cr><esc>
or something like this to silently write the current line
:nnoremap <silent> \c V:w !cmd<cr><esc>