freebsd-ports/shells/esh/pkg-plist

bin/esh
@exec echo "updating /etc/shells"; cp /etc/shells /etc/shells.bak; (grep -v %D/%F /etc/shells.bak; echo %D/%F) >/etc/shells
@unexec echo "updating /etc/shells"; cp /etc/shells /etc/shells.bak; (grep -v %D/%F /etc/shells.bak) >/etc/shells