#!/bin/bash
#author:zhanghongjun
#version:1.0
#date:2011年 12月 14日 星期三 21:18:18 CST


function information
{
    echo "---------------------------"
    echo "国家图书馆管理系统（5.4版本）"
    echo
    echo -n "| " ;echo "1:添加图书"
    echo -n "| " ;echo "2:删除图书"
    echo -n "| " ;echo "3:图书列表"
    echo -n "| " ;echo "4:查找图书"
    echo -n "| " ;echo "5|q:退出系统"
    echo
    echo "---------------------------"
    read -p "请输入你的选择:" a


    case "$a" in
    1)
        add ;;
    2)
        delete ;;
    3)
        list ;;
    4)
        search;;
    5|q|Q)
        return -1 ;;
    *)
        information ;;
    esac
}


function file_exist
{
    if [ ! -f .book.txt ];then
        touch .book.txt
    fi
}


function add
{
    read -p "请输入图书的编号：" number
    read -p "请输入图书的书名：" book_name
    read -p "请输入图书的作者：" author
    read -p "请输入图书的价格：" price 
        echo -e "$number\t$book_name\t$author\t$price" >>.book.txt && {
            echo "添加图书成功！"
            echo "-------------------"
        }
    if [ $? -ne 0 ];then
        echo "添加图书失败"
    fi
    information

}

function delete
{
    read -p "请输入要删除的图书的编号：" number
    grep $number .book.txt &>/dev/null && {
            sed -i '/\<'$number'\>/d' .book.txt &>/dev/null  &&
            echo "删除图书成功"
    echo "-------------------------"
    }

    if [ $? -ne 0 ];then
        echo "删除图书失败"
        echo "你要删除的图书不存在"
    fi
    information
}

#列出所有图书的信息
function list
{
    echo -e "编号\t书名\t作者\t价格"
    cat .book.txt
    echo "----------------------------"
    information

}


#下面的函数用到的查询菜单
function search_menu
{
    echo;echo "----------------------------"
    echo -n "|";echo -e "1：\t按图书编号查询"
    echo -n "|";echo -e "2：\t按图书书名查询"
    echo -n "|";echo -e "3：\t按图书作者查询"
    echo -n "|";echo -e "4：\t按图书价格查询"
    echo -n "|";echo -e "5|q：\t退出查询系统"
    echo;echo "----------------------------"

}
function search
{
    search_menu
    read -p "请输出你的选择：" myselect
    case "$myselect" in
    1)
        read -p "请输入要查询的图书的编号：" mynumber
        echo -e "编号\t书名\t作者\t价格\n"
        awk '$1=='$mynumber'{print $0}' .book.txt 2>/dev/null

        if [ $? -ne 0 ];then
            echo "图书不存在"
        fi
        search
        ;;
    2)
        read -p "请输入你要查询的书名：" mybook_name
        echo -e "编号\t书名\t作者\t价格\n"
        awk '$2~/'$mybook_name'/{print $0}' .book.txt 2>/dev/null
        if [ $? -ne 0 ];then
            echo "图书不存在"
        fi
        search
        ;;
    3)
        read -p "请输入图书的作者：" myauthor
        echo -e "编号\t书名\t作者\t价格\n"
        awk '$3~/'$myauthor'/{;print $0}' .book.txt 2>/dev/null
        if [ $? -ne 0 ];then
            echo "图书不存在"
        fi
        search
        ;;
    4)
        read -p "请输入图书的价格：" myprice
        echo -e "编号\t书名\t作者\t价格\n"
        awk '$4=='$myprice'{print $0}' .book.txt 2>/dev/null
        if [ $? -ne 0 ];then
            echo "图书不存在"
        fi
        search
        ;;
    5)
        information
        ;;
    *)
        information
        ;;
    esac

}

information