VIM: How to call a vimscript function after press a shortcut or execute a command?

Question

I want to know how to call a function after a normal or Ex command.

Examples:

• bind a function to search command. When I input /xxxx to search xxxx, also call the function.
• press * to highlight occurrences, then also execute a function.

Answer 1

In case of * (or similar normal mode commands) you just remap it:

func! MyFunc()
    echom "Hello World"
endfunc

nnoremap * *:call MyFunc()<CR>

For the search /xxxx you can redefine <CR> mapping in commandline:

func! SearchCR()
    if getcmdtype() =~ "[/?]"
        echom "Run Something if CR was pressed in /search"
    endif
endfunc

cnoremap <CR> <cmd>call SearchCR()<CR><CR>

This would work only in recent vim (with support of a new <cmd>)

PS, there are no "hooks" in vim to attach to selected normal mode commands, although there are autocommands that could be used to run your code on some events.