freebsd-ports/news/ifmail/pkg-install

#!/bin/sh

user=ifmail
group=uucp
uid=70

ask() {
    local question default answer

    question=$1
    default=$2
    if [ -z "${PACKAGE_BUILDING}" ]; then
	read -p "${question} [${default}]? " answer
    fi
    if [ x${answer} = x ]; then
	answer=${default}
    fi
    echo ${answer}
}

yesno() {
    local dflt question answer

    question=$1
    dflt=$2
    while :; do
	answer=$(ask "${question}" "${dflt}")
	case "${answer}" in
	[Yy]*)		return 0;;
	[Nn]*)		return 1;;
	esac
	echo "Please answer yes or no."
    done
}

case $2 in

PRE-INSTALL)

    if which -s pw; then
	:
    else
	cat <<EOF

This system looks like a pre-2.2 version of FreeBSD.  I see that
it is missing the "pw" utility.  I need this utility.  Please get
it and install it, and try again.  You can get the sources from:

  ftp://ftp.freebsd.org/pub/FreeBSD/FreeBSD-current/src/usr.sbin/pw.tar

EOF
	exit 1
    fi
    
    if pw user show "${user}" 2>/dev/null; then
	echo "You already have a user \"${user}\", so I will use it."
    else
	echo "You need a user \"${user}\"."
	if which -s pw && yesno "Would you like me to create it" y; then
	    if [ `id -u` -ne 0 ]; then
		echo "You must be root to add the user."
		exit 1
	    fi
	    if pw user show ${uid} >/dev/null 2>&1; then
		echo "The ifmail user is normally UID ${uid}.  However, you currently have"
		echo "a UID ${uid}."
		if yesno "Should I just pick a new UID" y; then
		    while pw user show ${uid} >/dev/null 2>&1; do
			uid=`expr ${uid} + 1`
		    done
		    if [ $uid -gt 99 ]; then
			echo "I can't find a low UID to use.  Please create an 'ifmail' user"
			echo "and try the installation again."
			exit 1
		    fi
		else
		    exit 1
		fi
		echo "Ok, I'll use UID ${uid}."
	    fi
	    pw useradd ${user} -g ${group} -u ${uid} -h - -d /nonexistent \
		-s /nonexistent -c "Ifmail user" || exit 1
	    echo "Done."
	else
	    echo "Please create it, and try again."
	    exit 1
	fi
    fi

    ;;

#
# The package system untar's the file first, potentially before the
# ifmail user is created.  This means that the files in
# ${PREFIX}/libexec/ifmail will be setuid root, not setuid ifmail.
# We have to fix this up.
POST-INSTALL)
    chown ifmail ${PREFIX}/libexec/ifmail/*
    ;;
esac