Hello, i have a script which checks if the user entered 8 numeric characters in the form of YYYYMMDD (birth date). If the user entered any non numeric characters, an error will be displayed:

# Check to see if the 8 characters are all numbers
# If not show error essage
# And prompt user for more input

         echo $char | grep -q '^[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]$'  
if 	[ $? -ne 0 ]
then
         echo "You have entered non-numeric values.  Please type in the form of YYYYMMDD"
	read char
        continue