freebsd-ports/mail/imap-uw/pkg-install

#!/bin/sh
TTY=/dev/tty

if [ "X$PACKAGE_BUILDING" != "X" ]; then
    exit 0
fi

case $2 in
    POST-INSTALL)
	;;
    PRE-INSTALL)
	if dialog --yesno "This port is not safe to use on a system which does not\nprovide shell access to users who can retrieve mail via IMAP.\nimapd contains buffer overflows which a user can exploit\nafter they have logged into imap to get access to their\naccount on the machine. If your imap users have shell access\nanyway, this is not a significant vulnerability.\n\nThere is also a vulnerability wherein local users can prevent\narbitrary POP2/3 mailboxes from being opened, and force IMAP\nmailboxes to only open read-only.\n\nDo you wish to proceed with the build?" 16 65 < ${TTY} >${TTY} 2>&1; then
	    exit 0
	else
	    exit 1
	fi
	;;
    *)
	echo "Unexpected argument $2!"
	exit 1
	;;
esac
exit 0