Shell Programming and Scripting

#!/bin/bash
#
#  complete add user script
#
initialize_variables ()
{
noinput=
user_id=' '
user_id_num=' '
home_directory=' '
group_id_num=' '
group_name=' '
#
#
cat /u/reedk/ulist|cut -f3 -d':'|sort -bg > luid_file
#
tuid=$(tail -1 luid_file)
let user_id_num=$tuid+1
echo "$user_id_num"
}
#
display_heading ()
{
clear
echo "           ADD USER SCREEN        "
echo " _________________________________"
}
main_menu ()
{
   let doption=100
   while [ $doption != 99 ]
    do
     display_heading


echo "  1.  Enter user real name .................. $user_name       "
echo "      Next available user ID Number ......... $user_id_num     "
echo "  2.  Enter Group ID Number ................. $group_id_num    "
echo "                Group name .....$group_name"
echo "  3.  Enter Home Directory  ................. $home_directory  "
echo "  4.  Enter Default Shell  .................. $default_shell   "
echo " "
echo " user_add -c "$user_name" -d $home_directory -g $group_id_num -G $group_name -m -s $default_shell $strt_script "
echo " "
echo "  0.  ADD USER NOW  "
echo " "
echo " "
echo "  99.  EXIT   (Take no action)  "
echo " ============================================================"
echo " Please select an option ===>   "
read option
case $option in
  0)  echo " user_add -c "$user_name" -d $home_directory -g $group_id_num -G $group_name -m -s $default_shell $strt_script "
      echo " $user_name has been added successfully"
      sleep 5
     ;;
  1)  display_heading
      echo "Please the users real name: (fi.mi.last)  ==>  "
      read confirm_reply
      if [ "$confirm_reply" = "$noinput" ]
         then
           echo " No user name entered"
         else
           user_name=$confirm_reply
           home_directory=/u/$user_name
           default_shell=/bin/bash
           if [ "$user_name" = "$( cat /u/reedk/ulist|cut -f1 -d':'|grep $user_name) " ]
             then
              echo " User name already exists"
           fi
      fi
      ;;
  2)  display_heading
      echo "Enter the primary Group ID Number ==>  "
      read confirm_reply
      group_name=' '
      if [ "$confirm_reply" = "$noinput" ]
        then
         echo "No primary group ID was entered"
        else
         grpfnd='n'
         group_id_num=$confirm_reply
         for i in $(cat /u/reedk/gfile|cut -f1,3 -d':')
          do
            if [ $(echo $i|cut -f2 -d':') -eq $group_id_num ]
             then
               grpfnd='y'
               group_name=$(echo $i|cut -f1 -d':')
            fi
            done
            if [ $grpfnd = 'n' ] || [ $group_id_num -eq 0 ]
              then
               echo "Invalid primary group number entered"
            fi
      fi
      ;;
  99)  let doption=99
       ;;
esac
done
}
#
###################################
#  BEGIN MAIN PROGRAM             #
###################################
if [ "$(whoami)" != "$( cat /u/reedk/auth.list|grep $(whoami) )" ]
   then
     echo " You are not authorized to run this script ... Contact your System Administrator "
   else
     initialize_variables
     main_menu
fi

set -x