该电话本可以实现以下功能

1.添加用户

2.查询用户

3.删除用户

4.展示用户

5.退出

代码展示：

#!/bin/bash
 
PHONEBOOK=phonebook.txt
 
function add_contact() {
    echo "Adding new contact..."
    read -p "Enter name: " name
    read -p "Enter phone number: " number
    echo "$name:$number" >> $PHONEBOOK
    echo "Contact added successfully."
}
 
function search_contact() {
    echo "Searching for contact..."
    read -p "Enter name to search: " search_name
    if grep -q "$search_name" $PHONEBOOK; then
        grep "$search_name" $PHONEBOOK
    else
        echo "Contact not found."
    fi
}
 
function list_contacts() {
    echo "Listing all contacts..."
    if [ -s "$PHONEBOOK" ]; then
        cat $PHONEBOOK
    else
        echo "Phonebook is empty."
    fi
}
 
function delete_contact() {
    echo "Deleting contact..."
    read -p "Enter name of contact to delete: " del_name
    if grep -q "$del_name" $PHONEBOOK; then
        sed -i "/$del_name/d" $PHONEBOOK
        echo "Contact deleted successfully."
    else
        echo "Contact not found."
    fi
}
 
function main_menu() {
    echo "1. Add Contact"
    echo "2. Search Contact"
    echo "3. List Contacts"
    echo "4. Delete Contact"
    echo "5. Exit"
    read -p "Enter your choice: " choice
    case $choice in
        
            add_contact
            main_menu
            ;;
        
            search_contact
            main_menu
            ;;
        
            list_contacts
            main_menu
            ;;
        
            delete_contact
            main_menu
            ;;
        
            echo "Exiting phonebook program."
            exit 0
            ;;
        *)
            echo "Invalid choice."
            main_menu
            ;;
    esac
}
 
main_menu

应用展示：