#compdef newgrp groupdel

local expl groups tmp

_tags groups || return 1

if ! zstyle -a ":completion:${curcontext}:" groups groups; then
  (( $+_cache_groups )) ||
      if [[ $OSTYPE = darwin* ]]; then
        : ${(A)_cache_groups:=${${(M)${(f)"$(_call_program groups lookupd -q group)"}:#name*}##*: }}
      elif (( ${+commands[getent]} )); then
        : ${(A)_cache_groups:=${${(s: :)$(_call_program groups getent group 2>/dev/null)}%%:*}}
      else
        : ${(A)_cache_groups:=${${${(s: :)$(</etc/group)}%%:*}:#+}}
	if (( ${+commands[ypcat]} )) &&
	    tmp=$(_call_program groups ypcat group.byname 2>/dev/null); then
          _cache_groups+=( ${${(f)tmp}%%:*} ) # If you use YP
	fi
      fi

  groups=( "$_cache_groups[@]" )
fi

_wanted groups expl group compadd "$@" -a groups