Allows the user to add/edit/delete user accounts on the system

user_management.sh

#!/bin/bash

# User Management script that allows the user to add/edit/delete
# user accounts on the system. Must be run with root privileges.
# Requires mkpasswd to be installed.
#
# Author: Pavan Chander
# Revision: 0.7
# Last update: 2013-11-18 

header()
{
  clear
  echo "USER MANAGEMENT"
  echo "==============="
}

main_menu()
{
  echo "Pick a function"
  echo "1) Add a user"
  echo "2) Edit a user"
  echo "3) Delete a user"
  echo "q) Quit"

  echo -n "> "
  read menu_option

  case $menu_option in
    1 ) add_user
        ;;
    2 ) edit_user
        ;;
    3 ) delete_user
        ;;
    q ) echo "Bye!"
        ;;
    * ) header
        echo "Error: Invalid entry, try again!"
        main_menu
  esac
}

add_user()
{
  header
  echo "Adding a user"
  echo -n "Username: "
  read user
  
  if [ -z "$(getent passwd $user)" ]; then
    # User doesn't exist, proceed with user creation
    echo -n "Password: "
    read password
    
    echo -n "Comment: "
    read comment
    
    useradd -m -p `mkpasswd $password` -U -s /bin/bash -c "$comment" "$user"

    if [ $? == 0 ]; then
      header
      echo "${user} was successfully added"
      main_menu
    else
      header
      echo "Error: There was a problem creating ${user}"
      main_menu
    fi
  else
    header
    echo "Error: User already exists!"
    main_menu
  fi
}

edit_user()
{
  header
  echo "Editing a user"
  
  # Make sure a username is provided
  user=""
  while [ -z "$user" ]
  do
    echo -n "Username: "
    read user
   done
    
  if [ -z "$(getent passwd $user)" ]; then
    # User doesn't exist
    
    header
    echo "ERROR: That was not a valid user!"
    main_menu
  else
    orig_shell=`getent passwd $user | cut -f7 -d:`
    orig_comment=`getent passwd $user | cut -f5 -d:`
  
    header
    echo "Editing ${user}"
    
    read -e -p "Shell: " -i "${orig_shell}" shell    
    read -e -p "Comment: " -i "${orig_comment}" comment
    usermod -c "$comment" -s "$shell" $user
    
    if [ $? == 0 ]; then
      header
      echo "Changes to ${user} have been saved"
      main_menu
     else
      header
      echo "Error: There was a problem saving changes to ${user}!"
      main_menu
     fi
  fi 
}

delete_user()
{
  header
  echo "Deleting a user"
  echo -n "Username: "
  read user
  
  if [ -z "$(getent passwd $user)" ]; then
    # User doesn't exist
    header
    echo "Error: That user doesn't exist!"
    main_menu
  else
  
    echo "Are you sure you want to delete ${user}?"
    echo -n "Please type 'yes': "
    read confirmation
    
    if [ "$confirmation" == "yes" ]; then
      userdel -r "$user"
      
      if [ $? == 0 ]; then
        header
        echo "${user} has been deleted"
        main_menu
       else
        header
        echo "Error: There was a problem deleting ${user}!"
        main_menu
       fi
    else
      header
      echo "Warning: ${user} was not deleted"
      main_menu
    fi
  fi
}

if [ $EUID != 0 ]; then
    echo "Error: User manipulation requires root privileges"
    exit 126
fi

header
main_menu