Realizing an address
book The address book can be used to store the information of people with a certain capacity. When the maximum capacity is stored, the address book will automatically expand, and the address book in the program should be persisted to the hard disk or database every time the program is closed.
Provision:
1, add contact information
2, to delete the specified contacts
3, shows all contacts
4, specify the contact information modification
5, to display all contacts
6, clear all contacts
0, address book program exits
relates Knowledge points obtained:
Multiple files, applications in structures, applications of flexible arrays, use of static keywords, dynamic memory management, use of file pointers to persist and read data, etc.
The header file is as follows:
#include "contact.h"
int main()
{
//初始化通讯录
contact_t* ct = InitContact();
int quit = 0;
int select = 0;
while (!quit){
Menu();
printf("please input your select:");
scanf("%d", &select);
switch (select)
{
case 1:
AddPerson(&ct);
break;
case 2:
DelPerson(ct);
break;
case 3:
break;
case 4:
break;
case 5:
ShowContact(ct);
break;
case 6:
Clear(ct);
break;
case 7:
break;
default:
quit = 1;
SaveContact(ct);//在通讯录退出的时候保存通讯录到硬盘
break;
}
}
printf("ByeBye!\n");
system("pause");
return 0;
}
Definition of related functions in the header file:
#include"contact.h"
void Menu()
{
printf("###################################\n");
printf("##1.Add 2.Del 3.Search 4.Mod####\n");
printf("##5.Show 6.Clear 7.Sort 0.Exit###\n");
}
//初始化结构体
contact_t* InitContact(){
contact_t *ct = NULL;
FILE* fp = fopen(SAVE_FILE, "rb");
if (NULL == fp)
{
printf("use default:init Contact ing...\n");
int size = sizeof(contact_t)+sizeof(person_t)*NUM;
ct = (contact_t*)malloc(size);
if (NULL == ct){
printf("Contact malloc error!\n");
exit(1);
}
ct->cap = NUM;
ct->size = 0;
printf("use default:init Contact done!\n");
}
else{
//读入通讯录
printf("read in contact from disk ing....\n");
contact_t temp;
fread(&temp, sizeof(contact_t), 1, fp);
int size = sizeof(contact_t)+sizeof(person_t)*temp.cap;
ct = (contact_t*)malloc(size);
if (NULL == ct){
printf("Contact malloc error!\n");
exit(1);
}
ct->cap = temp.cap;
ct->size = temp.size;
//先把通讯录头读进来，知道cap和size,就可以申请空间了，
//申请完空间再把柔性数组中的人读到我申请的堆空间里
fread(ct->persons, sizeof(person_t), temp.size, fp);
fclose(fp);
printf("read in contact from disk done....\n");
}
return ct;
}
static int FindPerson(contact_t* ct, const char* tel){
assert(ct&&tel);
int i;
for (i = 0; i < ct->size; i++){
if (strcmp(ct->persons[i].tel, tel) == 0){
return i;
}
}
return -1;
}
static int IsFull(contact_t* ct){
return ct->cap == ct->size;
}
static int Inc(contact_t ** ct){
printf("contact is full,incing....\n");
*ct = (contact_t *)realloc(*ct, sizeof(**ct) + INC_SIZE*sizeof(person_t));
if (NULL == *ct){
return 0;
}
((*ct)->cap) += INC_SIZE;
printf("contact is full,inc done....\n");
return 1;
}
void AddPerson(contact_t** ct){
if (!IsFull(*ct) || Inc(ct)){
//正常添加
person_t* p = &((*ct)->persons[(*ct)->size]);
//姓名，性别，年龄，电话，住址
printf("姓名：");
scanf(" %s", p->name);
printf("性别：");
scanf(" %c", &(p->sex));
printf("年龄：");
scanf(" %d", &(p->age));
printf("电话:");
scanf(" %s", p->tel);
printf("住址：");
scanf(" %s", p->addr);
(*ct)->size += 1;
}
else{
//空间满了，申请又失败了
printf("inc error!\n");
}
}
void ShowContact(contact_t* ct){
assert(ct);
printf("| %10s|%10s\n |\n", "姓名", "电话");
for (int i = 0; i < ct->size; i++){
printf("| %10s | %10s\n |\n", ct->persons[i].name, ct->persons[i].tel);
}
}
static int IsEmpty(contact_t* ct){
return ct->size == 0;//1为空，0为非空
}
void DelPerson(contact_t* ct){
assert(ct);
if (!IsEmpty(ct)){
printf("请输入你要删除人的电话:");
char tel[SIZE / 6] = {
0};
scanf(" %s", tel);
int pos = FindPerson(ct, tel);
if (pos >= 0){
ct->persons[pos] = ct->persons[ct->size - 1];
ct->size -= 1;
}
else{
printf("你要删除的人不存在！\n");
}
}
else{
printf("通讯录为空！\n");
}
}
void Clear(contact_t* ct){
ct->size = 0;
}
void SaveContact(contact_t* ct){
assert(ct);
FILE* fp = fopen(SAVE_FILE, "wb");
if (NULL == fp){
printf("file open error and save failure!\n");
}
//将用通讯录结构体和里面的柔性数组分别写入到硬盘中
fwrite(ct, sizeof(contact_t), 1, fp);
fwrite(ct->persons, sizeof(person_t), ct->size, fp);
fclose(fp);
}
``
main.c主要框架的设计
```c
#include "contact.h"
int main()
{
//初始化通讯录
contact_t* ct = InitContact();
int quit = 0;
int select = 0;
while (!quit){
Menu();
printf("please input your select:");
scanf("%d", &select);
switch (select)
{
case 1:
AddPerson(&ct);
break;
case 2:
DelPerson(ct);
break;
case 3:
break;
case 4:
break;
case 5:
ShowContact(ct);
break;
case 6:
Clear(ct);
break;
case 7:
break;
default:
quit = 1;
SaveContact(ct);//在通讯录退出的时候保存通讯录到硬盘
break;
}
}
printf("ByeBye!\n");
system("pause");
return 0;
}
Some function designs are not very rigorous. Interested friends can improve the functions based on my code. For example, when inputting gender, I did not check the accuracy of the input, and only input f and m.