PREIN

/bin/sh

getent group clamscan >/dev/null || groupadd -r clamscan
getent passwd clamscan >/dev/null || \
    useradd -r -g clamscan -d / -s /sbin/nologin \
    -c "Clamav scanner user" clamscan
exit 0

POSTIN

/bin/sh

/bin/systemd-tmpfiles --create /etc/tmpfiles.d/clamd.scan.conf || :