PREIN

/bin/sh

getent passwd sems >/dev/null || \
/usr/sbin/useradd -r -c "SIP Media Server"  -d /var/spool/sems -s /sbin/nologin sems 2>/dev/null || :

PREUN

/bin/sh

if [ $1 -eq 0 ] ; then 
        # Package removal, not upgrade 
        /usr/bin/systemctl --no-reload disable sems.service > /dev/null 2>&1 || : 
        /usr/bin/systemctl stop sems.service > /dev/null 2>&1 || : 
fi

POSTIN

/bin/sh

if [ $1 -eq 1 ] ; then 
        # Initial installation 
        /usr/bin/systemctl preset sems.service >/dev/null 2>&1 || : 
fi