Shell Programming and Scripting

#!/bin/ksh
printf 'Do you want to start looping (Y<enter> to continue; anything else to stop)?: '
read response
while [ "$response" = "Y" ]
do	printf '\nOK\n'
	# Do whatever you want to do here...
	printf 'Do you want to go again (Y<enter> to continue; anything else to stop)?: '
	read response
done
echo 'Goodbye.'

read -p

#!/bin/ksh
# bash/ksh93/zsh/... but not dash (=posix)

# if read key ENTER, bash return newline and ksh return carriage return
cr=$'\r'  # ENTER key ksh
while printf "Continue:Y\b"
      read -n 1 response
      printf "\r                  \n"
      case "$response" in
                $cr|Y|y|"") response="Y" ;; # default = ENTER
                n|N) reponse="N" ;;
                *) response="N" ;;
      esac
      [ "$response" = "Y" ]
do
                echo "Do ..."
                date
                echo "..."
done

echo 'Goodbye.'

# keypressed, read 1 char from stdin using dd
# works using any sh-shell
readkbd() {
  stty -icanon -echo
  dd bs=1 count=1 2>/dev/null
  stty icanon echo
}

while printf "Continue:Y\b"
      response=$(readkbd)
      printf "\r                  \n"
      case "$response" in
                Y|y|"") response="Y" ;; # default = ENTER
                n|N) reponse="N" ;;
                *) response="N" ;;
      esac
      [ "$response" = "Y" ]
do
                echo "Do ..."
                date
                echo "..."
done

echo 'Goodbye.'