Cal app for Linux

#!/bin/bash

function main {
  `echo clear`
  echo "Phonebooks on record:"
  `echo find ~ -type f -name \*.dat`
  echo ""
  echo "Please select which phonebook" 
  echo "you would like to modify."
  echo "Or you can create a newfile"
  echo "by typing in the path" 
  echo "and the name of the file" 
  printf "with the .dat extension\n>"
  read phonebook_name 
  menu 
}

function menu { 
  `echo clear`
  echo "Phonebook: $phonebook_name."
  echo ""
  echo "Select 1, 2, 3 or 4."
  echo "========================="
  echo ""
  echo "1) add an entry"
  echo "2) delete an entry"
  echo "3) list file or entry"
  echo "4) change entry"
  echo "5) exit system"
  echo "6) switch phonebook"
  echo ""
  echo "========================="

  printf "What is your choice?\n>"
  read choice
  if [ $choice = 1 ] 
  then
    addEntry
  elif [ $choice = 2 ]
  then 
    deleteEntry
  elif [ $choice = 3 ]
  then
    listEntry
  elif [ $choice = 4 ]
  then
    changeEntry
  elif [ $choice = 5 ]
  then
    endProgram
  elif [ $choice = 6 ]
  then 
    main 
  else
    echo "I'm sorry, I'm afraid I can't do that."
    menu 
  fi 
}
  
function addEntry {
  printf "Enter a name to add\n>"
  read contact_name 
      
  printf "Enter a phone number to add\n>"
  read phone_number 
  
  echo "The added entry would be $contact_name: $phone_number."
  `echo $contact_name: $phone_number >> $phonebook_name`
   
  printf "Would you like to add another? [y/n]\n>"
  read add_another
      
  if [ $add_another = "y" ] || [ $add_another = 'Y' ]
  then 
    addEntry
  elif [ $add_another = 'yes' ] || [ $add_another = 'YES' ]
  then
    addEntry
  elif [ $add_another = 'n' ] || [ $add_another = 'N' ]
  then
    menu
  elif [ $add_another = 'no' ] || [ $add_another = 'NO' ]
  then 
    menu
  else 
    echo "Uh, I think that means you don't want to"
    endProgram
  fi 
}

function deleteEntry {
  printf "Enter name to delete\n>"
  read name_to_delete
  
  # return line that equals name 
  
  # if there are two matches, then have them select which one 
}

function listEntry {
  echo ""
  echo "1) list entry"
  echo "2) list file"
  echo "3) back"
  echo ""
  printf ">"
  
  read what_to_list
  
  if [ $what_to_list = 1 ] 
  then 
    `echo cat $phonebook_name`
    listEntry
  elif [ $what_to_list = 2 ] 
  then 
    printf "What name do you want to search for?\n>"
    read which_entry
    `echo grep '$which_entry' $phonebook_name`
    grep 'Tim' phonesys.dat
  elif [ $what_to_list = 3 ]
  then
    menu
  else 
    echo "Didn't understand that! Enter 1, 2 or 3"
    listEntry
  fi 
}

function changeEntry {
  printf "Enter a name or a number that you want to edit\n>"
  read what_to_change
  
  # search file for phrase 
  
  # allow ability to edit 
  
  # pipe back to .dat file 
  
  
  
  
}

function endProgram {
  `echo clear`
  echo "Goodbye!"
  exit 0
}
  
main 
  

In process of building