Shell Programming and Scripting

ConfY_N=Y
ConfY_N=N
## Prompt Arg4
##
prompt_IM_StartDt ()
{
 echo -e "\n\nUser will enter Start Time here : ";
 read IM_StartDt;
}
##
## Set Arg4
##
set_IM_StartDt ()
{
 ## Fetching Start Date for Product Classification folder.
 IM_StartDt="";
 if [[ -z "${IM_StartDt}" ]]; then prompt_IM_StartDt; fi
}
# ----------------------------------------------------------------------------------------------------------------
## Prompt Arg5
##
prompt_IM_CloseDt ()
{
 echo -e "\n\nUser will enter Start Time here : ";
 read IM_CloseDt;
}
##
## Set Arg5
##
set_IM_CloseDt ()
{
 ## Fetching Close Date for Product Classification folder.
 IM_CloseDt="";
 if [[ -z "${IM_CloseDt}" ]]; then prompt_IM_CloseDt; fi
## Give priority to passed parameters first.
IM_StartDt="${1}";
IM_CloseDt="${2}";

#copy ()
#{
#mv ${IM_StartDt} ${IM_CloseDt}
#}
## Check arguments and set them if reqd.
## -------------------------------------
for arg in IM_StartDt:${IM_StartDt} IM_CloseDt:${IM_CloseDt};
do
  ## Get Var/Val pair
  var="${arg%:*}";
  val="${arg#*:}";
  ## Check IM variable null condition. If not set, find it from Master config file. If Master config file doesn't store the value, prompt the user (last option).
  if [[ -z "${val}" ]]; then
     set_${var};
  fi
done
#copy
until [[ $ConfY_N == "Y" ]];
do
  echo -e "\n\n\n#########################################################################################################\n";
  echo -n "- User Confirmation required, please enter (Y to continue -OR N to stop/exit gracefully): "; read ConfY_N;
                
## DONT show the below echo on Screen STDOUT. Use >>.
  ConfY_N="$(echo ${ConfY_N} | tr a-z A-Z)";
  echo -e "\n# User Selected: \"${ConfY_N}\" ####################################################################################\n\n\n";
  copy
  if [[ "${ConfY_N}" == "N" ]];
  then
      echo -e "User requested to EXIT out gracefully.\n\n";
      #echo -e "`show_script_data`";);
      exit;
      fi
done
copy ()
{
mv ${IM_StartDt} ${IM_CloseDt}
}

read ConfY_N

read a < /dev/tty

until false
do
  echo -e "\n\n\n###############################################################
##########################################\n";
  read -p "- User Confirmation required, please enter (Y to continue -OR N to st
op/exit gracefully): " ConfY_N;

  echo -e "\n# User Selected: \"${ConfY_N}\" ###################################
#################################################\n\n\n";
  # copy
  if [[ "${ConfY_N}" == "N" || $ConfY_N == 'n' ]]; then
      echo -e "User requested to EXIT out gracefully.\n\n";
      exit 0;
  fi
done