post_install() {
    if [ -z "`grep '^ushare:' /etc/group`" ]; then
        groupadd -r ushare
    fi
    if [ -z "`grep '^ushare:' /etc/passwd`" ]; then
        useradd -r -d /var/empty -g ushare -s /sbin/nologin ushare
    fi
}

post_upgrade() {
    post_install $1
}

post_remove() {
    userdel ushare
    groupdel ushare
}