_zimfw_mv() {
  local -a cklines
  if cklines=(${(f)"$(command cksum ${1} ${2} 2>/dev/null)"}) && \
      [[ ${${(z)cklines[1]}[1,2]} == ${${(z)cklines[2]}[1,2]} ]]; then
    _zimfw_print -PR "<%= okay %>%B${2}:%b Already up to date"
  else
    if [[ -e ${2} ]]; then
      command mv -f ${2}{,.old} || return 1
    fi
    command mv -f ${1} ${2} && _zimfw_print -PR "<%= okay %>%B${2}:%b Updated.${_zrestartmsg}"
  fi
}