echo "Would you like to continue (yes/no)?"
case $REPLY in
yes|y) do something;;
no|n) do something else;;
Getkey command is useful
see example below
getkey -c 10 -m "please enter yes to continue.." y
-c 10 means timeout 10 seconds
y means, user must enter y in 10 seconds
Read -p " Do you want to continue(y/n)? " ANS
case $ANS in
#do some commands..
echo user did not enter Y/y/yes/YES
#do some other commands