PREIN

/bin/sh

if [ $1 == 1 ]; then
    /usr/sbin/useradd -c "Nginx user" -s /bin/false -r -d /var/lib/nginx nginx 2>/dev/null || :
fi

PREUN

/bin/sh

if [ $1 = 0 ]; then
    /sbin/service nginx stop >/dev/null 2>&1
    /sbin/chkconfig --del nginx
fi

POSTIN

/bin/sh

if [ $1 == 1 ]; then
    /sbin/chkconfig --add nginx
fi

POSTUN

/bin/sh

if [ $1 == 2 ]; then
    /sbin/service nginx upgrade || :
fi