C language address book system, for your reference, the specific content is as follows
Demand analysis:
Use the method of file reading and writing
Add address book contact information
Delete contact information in the address book
Realize to find contact information in the address book
Implement modification of address book contact information
Implementation to view existing address book contact information
Code implementation:
// main.c
// C Language address book implementation
//
// Created by Brisinga on 15/10/14.
// Copyright © 2015 years yan. All rights reserved.
//
#include <stdio.h>
#include<string.h>
#define LEN 10
#define NAMELEN 22
#define TELLEN 12
//************* Structure variable definition ****************
// Define the number of contacts
int contactCount = 0;
// Define structure
typedef struct{
// Define contact name
char name[NAMELEN];
// Define contact number
char tel[TELLEN];
}Person;
// Initializes the contact group
Person contact[LEN];
// Define filename
charchar *path = "a.data";
// Receive the user's input number
int no;
//************** Function declaration ********************
// Initialization declaration
void init();
// Check the statement
int isValid(int n,int min,int max);
// Add contacts
void addContact();
// Delete contacts
void deleteContact();
// Modify contact
void updateContact();
// View all contacts
void doList();
// Search contacts
void searchContact();
// Log out
void quit();
// Contact write file
void writeFile();
//***************************************
int main(int argc, const charchar * argv[]) {
// Address book initialization
init();
printf(" Address book initialization succeeded! \n");
while (1) {
// Define the interface
printf("**********************************\n");
printf("*********** Welcome to the address book ***********\n");
printf("***********1. Add contacts *************\n");
printf("***********2. Delete contacts *************\n");
printf("***********3. Modify contact *************\n");
printf("***********4. View all contacts **********\n");
printf("***********5. Search contacts *************\n");
printf("***********6. Log out ***************\n");
printf("**********************************\n");
// Prompt the user for a number
printf(" Please enter the operation number: \n");
scanf("%d",&no);
// Determine if the input is valid
isValid(no, 1, 6);
// Determine the user's actions
switch (no) {
case 1:
// Add contacts
addContact();
break;
case 2:
// Delete contacts
deleteContact();
break;
case 3:
// Update contacts
updateContact();
break;
case 4:
// View contacts
doList();
break;
case 5:
// Search contacts
searchContact();
break;
case 6:
// exit
quit();
return 0;
default:
break;
}
}
return 0;
}
// Address book initialization
void init(){
// Definition file pointer
FILEFILE *fp = fopen(path, "r");
// Determine if the address book exists
if (fp!=NULL) {
// If there is
//1. Number of read contacts
fread(&contactCount, sizeof(contactCount), 1, fp);
//2. Read each 1 A contact nts
for (int i=0; i<contactCount; i++) {
fread(&contact[i], sizeof(Person), 1, fp);
}
}else{
// If it doesn't exist
// Create address book
fp = fopen(path, "wb");
// Writes the number of current contacts
fwrite(&contactCount, sizeof(contactCount), 1, fp);
}
fclose(fp);
}
// Verify that the input is valid
int isValid(int n,int min,int max){
// If the input number is greater than min Less than max, It returns 0
if (n>=min&&n<=max) {
return 0;
}
// Otherwise returns 1
printf(" Illegal import! \n");
return 1;
}
// Add contacts
void addContact(){
// The user is prompted for a name to add a contact
printf(" Please enter the name of the contact to be added: * Note that there should be no Spaces between names \n");
// Receiving contact name
scanf("%s",contact[contactCount].name);
// Prompt the user for the number to add
printf(" Please enter the number to add a contact: * Note that there should be no Spaces between the Numbers \n");
// Receive contact number
scanf("%s",contact[contactCount].tel);
// Ask if you are sure to add
printf(" Are you sure you want to add it? 1. determine 0. cancel \n");
scanf("%d",&no);
if (no) {
contactCount++;
// Written to the file
writeFile();
printf(" Added successfully! \n");
}
}
// Delete contacts
void deleteContact(){
// Show contacts
doList();
int flag;
// The user is prompted for the number of contacts to delete
printf(" Please enter the number of the contact to delete: \n");
// Receive the user's input number
scanf("%d",&no);
// Determine if the number is valid
if(!isValid(no, 1, contactCount)){
// Number the legitimate
printf(" Are you sure you want to delete it? It cannot be restored after deletion! 1. determine 0. cancel \n");
scanf("%d",&flag);
if (flag) {
// If the contact to be deleted is at the end
if (no==contactCount) {
// the contactCount-1
contactCount--;
}else{
// If the contact to be deleted is not at the end
// Move array elements
for (int i=no-1; i<contactCount-1; i++) {
contact[i]=contact[i+1];
}
}
//contactCount--
contactCount--;
// Write files
writeFile();
}
}else
// The number is illegal, exit
printf(" The number is illegal! \n");
return ;
}
// Modify contact
void updateContact(){
// Show contacts
doList();
// Prompt the user for the number of contacts to change
printf(" Please enter the number of the contact to be modified: \n");
// Receive the user's input number
scanf("%d",&no);
// Determine if the number is valid
int flag;
if (!isValid(no, 1, contactCount)) {
// Prompt the user for the name of the new contact
printf(" Please enter your new name: * Note: No Spaces between names \n");
// Receive the user's input name
scanf("%s",contact[no-1].name);
// Prompt the user for a new phone number
printf(" Please enter your new phone number: * Note: There should be no space between the phone Numbers \n");
// Receive the phone number entered by the user
scanf("%s",contact[no-1].tel);
// Is the user asked to confirm the change?
printf(" Are you sure you want to change it? 1. determine 0. cancel \n");
scanf("%d",&flag);
if (flag) {
// Write files
writeFile();
printf(" Contact modified successfully! \n");
}else{
printf(" The number is illegal!! \n");
return ;
}
}
}
// View all contacts
void doList(){
printf(" Display all contacts: \n");
printf(" Serial number \t The name \t The phone \n");
for (int i=0; i<contactCount; i++) {
printf("%d\t%s\t%s\n",i+1,contact[i].name,contact[i].tel);
}
}
// Search contacts
void searchContact(){
int flag = 1;
// Receive the user's input name
char searchName[NAMELEN];
// Receive calls entered by the user
char searchTel[TELLEN];
// Ask the user how to search
printf(" Please enter how to find: 1. Search by name 2. Look it up by phone number \n");
// Receive the user's search method
scanf("%d",&no);
if (no==1) {
// Ask the user to enter the name to look for
printf(" Please enter the name to find: \n");
scanf("%s",searchName);
for (int i=0; i<contactCount; i++) {
if (!strcmp(searchName,contact[i].name)) {
printf(" The contact you are looking for is: \n");
printf("%d\t%s\t%s\n",i+1,contact[i].name,contact[i].tel);
return ;
}else{
flag = 0;
}
}
}else if(no==2){
// Ask the user to enter the phone number they are looking for
printf(" Please enter the phone number you are looking for: \n");
scanf("%s",searchTel);
for (int i=0; i<contactCount; i++) {
if (!strcmp(searchTel,contact[i].tel)) {
printf(" The contact you are looking for is: \n");
printf("%d\t%s\t%s\n",i+1,contact[i].name,contact[i].tel);
return ;
}else{
flag = 0;
}
}
}else{
printf(" Illegal input! \n");
return ;
}
if (!flag) {
printf(" I'm sorry! The friend is not in the address book! \n");
}
}
// Log out
void quit(){
printf(" System is exiting ...\n");
printf(" System is out! \n");
}
// Contact write file
void writeFile(){
// Definition file pointer
FILEFILE *fp = fopen(path, "wb");
if (fp!=NULL) {
// Number of contacts written
fwrite(&contactCount, sizeof(contactCount), 1, fp);
// Write to each contact
for (int i=0; i<contactCount; i++) {
fwrite(&contact[i], sizeof(Person),1, fp);
}
}
fclose(fp);
}