Something

         #!/bin/bash 
         CARDTYPE=18
	INPUTNUM=0;
         while [  $CARDTYPE -lt 20 ]; do
             echo Testing card $CARDTYPE
		modprobe -r ivtv
		sleep 3
		modprobe ivtv cardtype=$CARDTYPE
		sleep 5
		while [ $INPUTNUM -lt 6 ]; do
			echo Testing card:$CARDTYPE input: $INPUTNUM
			ivtvctl -p$INPUTNUM
			cat /dev/video0 > card$CARDTYPE-input$INPUTNUM.mpg & sleep 3; kill $!
			sleep 4
	             	let INPUTNUM=INPUTNUM+1 
		done
		INPUTNUM=0;	
             let CARDTYPE=CARDTYPE+1 
         done