Josh's advise make me forward. i upgrade snapshots . and pkg_add zsh . then '/usr/local/share/zsh/5.0.5/functions/_genisoimage' appear .
head /usr/local/share/zsh/5.0.5/functions/_genisoimage is next . #compdef genisoimage _arguments \ '-nobak[do not include backup files]' \ '-no-bak[do not include backup files]' .... but i do not understand how to make genisoimage . i only imagine _a2ps has the same method . genisoimage make smaller image than mkisofs. so it is useful to burn DVD. --- tuyosi