Shell Programming and Scripting

while [ 1 -eq 1 ]; do
  echo -n "Please Enter Name Of .pem File To Be Checked [ENTER]: "
  read file

  if [ -f "$file" ]; then
    openssl x509 -text -in "$file"
  else
    echo "File Doesn't Exist: $file"
  fi

  echo -n "Do you wish to check another [y/n]: "
  read yn
  if [ "$yn" != "y" ]; then
    exit # from shell script
  fi
done

$ while read -p "Enter file name; <ctrl>D to end" file
     do  [ -f "$file" ] && openssl x509 -text -in "$file"  || echo "File Doesn't Exist: $file" 
     done