Zsh completion on the second command or after an alias

There is a great thread about this on the Ubuntu forums. Ole J proposes the following alias completion definition function:

function make-completion-wrapper () {
  local function_name="$2"
  local arg_count=$(($#-3))
  local comp_function_name="$1"
  shift 2
  local function="
    function $function_name {
      ((COMP_CWORD+=$arg_count))
      COMP_WORDS=( "$@" \${COMP_WORDS[@]:1} )
      "$comp_function_name"
      return 0
    }"
  eval "$function"
  echo $function_name
  echo "$function"
}

Use it to define a completion function for your alias, then specify that function as a completer for the alias:

make-completion-wrapper _apt_get _apt_get_install apt-get install
complete -F _apt_get_install apt-inst

I prefer to use aliases for adding always-used arguments to existing programs. For instance, with grep, I always want to skip devices and binary files, so I make an alias for grep. For adding new commands such as grepbin, I use a shell script in my ~/bin folder. If that folder is in your path, it will get autocompleted.

You can add your completer to the list of completers used by default:

zstyle ':completion:*' completer _last_command_args _complete