That is true, but with out the resident scanner there really is not need to have a cron job that updates the Virus Database if you don't need it. Really you only need to update Avast before you scan anything, and it is easy to make a shell scrip that will update and then scan using avast in the CLI.
#!bin/sh
#avast scanner script - Updates avast's VB then scans the systems HD
echo "Where to scan?"
echo "1. Scan in $HOME"
echo "2. Scan /"
echo "3. Pick where to scan"
read type
if [ $type = 1 ] ; then
echo "Updating Avast's VB"
sudo avast-update
echo "Scanning $HOME"
sudo avast ~
sleep 5
exit
else
if [ $type = 2 ] ; then
echo "Updating Avast's VB"
sudo avast-update
echo "Scanning /"
sudo avast /
sleep 5
exit
else
if [ $ type = 3 ] ; then
echo "Where to scan?"
read dir
if [ ! -d $dir ] ; then
echo "$dir not found, try again"
echo "Where to scan?"
read dir
if [ ! -d $dir ] ; then
echo "Sorry can't find $dir"
exit
else
echo "Updating Avast's VB"
sudo avast-update
echo "Scanning $dir"
sudo avast $dir
fi
fi
fi
fi
fi
Not really pretty, and that good to look at, made it in about 5 minutes from the top of my head so there may be some problems with it but it should work (Intended it to just be looked at really), but it will get the job done and with some changed it can easily be made into a cron or an alias for the avast command.