#compdef ftp ncftp ping rwho rup xping traceroute

local expl

: ${(A)hosts:=${(s: :)${(ps:\t:)${${(f)"$(</etc/hosts)"}%%\#*}##[:blank:]#[^[:blank:]]#}}}

_description expl host
compadd -M 'm:{a-zA-Z}={A-Za-z} r:|.=* r:|=*' "$@" "$expl[@]" - "$hosts[@]"