build_random_line ()
{
# This function extracts random characters
# from the KEYS array by using the RANDOM
# shell variable

C=1
LINE=
until (( C > 79 ))
do
   LINE="${LINE}${KEYS[$(($RANDOM % X + 1))]}"
   (( C = C + 1 ))
done

# Return the line of random characters

echo "$LINE"
}