#compdef killall killall5

if [[ $service = killall && "$OSTYPE" = (linux*|*bsd*|darwin*) ]]; then
  _alternative \
    'signals:: _signals -p' \
    'processes-names:process:{ compadd "$expl[@]" ${${${${(f)"$(_call_program processes-names ps ${${EUID/(#s)0(#e)/xa}//[0-9]#/}ho command 2> /dev/null)"//[][\(\)]/}:#(ps|COMMAND|-*)}%%\ *}:t} }'
else
  _signals -p
fi