Afnetworking server client

// Monitoring network status （AFNetworking）
import "ViewController.h"
// Introduce a third-party framework 
import "AFNetworking/AFNetworking.h"
@interface ViewController ()
@end
@implementation ViewController

(void)viewDidLoad {
  [super viewDidLoad];
  // Check network status 
  [self checkNetworkStates];
}
#pragma mark  Check network status 
-(void)checkNetworkStates{
  //1. We created a for testing url
  NSURL  url = [NSURL URLWithString:@"http://www.apple.com"];
  //2. Establish an operation management 
  AFHTTPRequestOperationManager operationManager = [[AFHTTPRequestOperationManager alloc]initWithBaseURL:url];
  //3. According to different network states , Go and deal with it 
  [operationManager.reachabilityManager setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
  switch (status) {
      case AFNetworkReachabilityStatusNotReachable:
          NSLog(@" Network not found ");
          break;
      case AFNetworkReachabilityStatusReachableViaWiFi:
          NSLog(@" adopt wifi Connect ");
          break;
      case AFNetworkReachabilityStatusReachableViaWWAN:
          NSLog(@" adopt 2G/3G/4G Connect ");
          break;
      case AFNetworkReachabilityStatusUnknown:
          NSLog(@" Unknown ");
          break;
      default:
          break;
  }
 
  }];
  // Start monitoring ( Monitor the changes of network status in real time )
  [operationManager.reachabilityManager startMonitoring];
}

// Server side 
import <Foundation/Foundation.h>
include<sys/socket.h>// Provide socket Functions and data structures 
include<netinet/in.h>// Define the data structure 
include <arpa/inet.h>// Provide IP Address translation function 
int main() {
    // Server order : socket->bind->listen->while(true) accept -> do while recv ->close
    int fd = socket(AF_INET, SOCK_STREAM, 0);// The protocol does not call 
    BOOL success = (fd != -1);
    struct sockaddr_in addr;// Represents the server 
    int err;
    // Server address setting 
    if(success){
        NSLog(@"socket success ");
        memset(&addr, 0, sizeof(addr));
        addr.sin_len = sizeof(addr);
        addr.sin_family = AF_INET;
        addr.sin_port = htons(1024);
        addr.sin_addr.s_addr = INADDR_ANY;
        // Binding 
        err = bind(fd, (const struct sockaddr )&addr, sizeof(addr));
        success = (err == 0);
    }
    if(success){
        NSLog(@"bind success ");
        //listen monitor 
        // The second parameter is the size of the queue waiting to receive connections . For example connect When you ask to come , After three handshakes, put the connection in the queue , Until it is accept Handle . If the queue is full , And when there are new connections , The other party may receive an error message （ In fact, it is a process of queuing , And the process of collection ）
        err = listen(fd,5);
        success = (err == 0);
    }
    if(success){
        NSLog(@"listen success ");
        while(true){
            struct sockaddr_in clientaddr;
            // Define a client socket , Socket used to get the received client 
            int clientfd;
            // Define an address length variable , Length of receiving client 
            socklen_t addrLen;
            addrLen = sizeof(clientaddr);
            NSLog(@" Be prepared to accept ");
            //accept function 
            // The second parameter is used to return the protocol address of the client .
            // The third parameter is the length of the protocol address 
            clientfd = accept(fd, (struct sockaddr )&clientaddr, &addrLen);
            success = (clientfd!= -1);
            if (success) {
                char buf[1024];
                ssize_t count;// Used to receive the return value of the function 
                ssize_t len = sizeof(buf);
                do{
                    //recv()  The number of bytes of data actually read into the buffer is returned successfully , Erroneous return －1.
                   count = recv(clientfd,buf,len,0);
                    if(count < 0){
                        NSLog(@" bye ");
                        break;
                    }
                    // Output 
                    NSString *str = [NSString stringWithCString:buf encoding:NSUTF8StringEncoding];
                    NSLog(@"%@",str);

            }while(strcmp(buf, "exit")!=0);
        }
 
//            clientaddr.sin_family = AF_INET;
//            clientaddr.sin_port = htons(1024);
//            clientaddr.sin_addr.s_addr ＝inet_addr("127.0.0.1");
            // Close client ： Just close the socket specific TCP Connect 

        close(clientfd);

    }
}
    return 0;

 
// client 
import <Foundation/Foundation.h>
include<sys/socket.h>// Provide socket Functions and data structures 
include<netinet/in.h>// Define the data structure 
include <arpa/inet.h>// Provide IP Address translation function 
int main() {
    // Client order :Socket->bind->connect->send->close
    // Create a socket 
    // Socket ： Source ip Address and purpose ip Address   as well as   Combination of source port number and destination port number . Used to identify the server requested by the client .
    //domain: Domain of definition , Currently only supported AF_INET(Internet The address format of )
    //type: Socket type description .SOCK_STREAM streaming (TCP),SOCK_DGRAM Datagram (UDP)
    //protocol: The protocol used by the socket , If you do not want to specify , You can use 0 Express 
    int fd = socket(AF_INET, SOCK_STREAM, 0);
    printf("%d\n",fd);
    // As long as it doesn't equal -1, Indicates that the creation was successful .
    BOOL success= (fd != -1);
    //sockaddr_in  Is the address form of socket in the network environment 
    struct sockaddr_in addr;
    // Create a shaping variable , Used to reflect errors in network connection 
    int err;

if(success){
    printf("socket success \n");
    // Memory initialization 
    //sizeof: Calculate the number of bytes in the data space 
    memset(&addr,0,sizeof(addr));
    // Yes addr Structure 
    addr.sin_family = AF_INET;//AF_INET adopt Ipv4 communicate 
    // Set the network address 
    addr.sin_addr.s_addr =INADDR_ANY;//INADDR_ANY The specified address is 0.0.0.0 The address of . Indicates an indefinite address , Or imagine a “ Any address ”.
    // take socket Bind to a specific host address and port number , Successful binding will return , Failure can also 
    err = bind(fd, (const struct sockaddr *)&addr, sizeof(addr));
    success = (err == 0);//if(err == 0){success = true;}
}

if (success) {
    printf("bind success \n");

    // Create the server address to connect to 
    struct sockaddr_in serveraddr;
    // Memory initialization 
    memset(&serveraddr, 0, sizeof(serveraddr));
    // Set structure  （host to net short）
    serveraddr.sin_port = htons(1024);// Converts the unsigned short integer of the host to network byte order 
    serveraddr.sin_len = sizeof(serveraddr);
    serveraddr.sin_family = AF_INET;
    // Set the server address 
    serveraddr.sin_addr.s_addr = inet_addr("127.0.0.1");// This address is local , Generally used to test the use of .
    printf(" Connecting ...\n");

    // The client sends a connection request to the server , Connection successful return 0, Failure to return －1
    err = connect(fd, (const struct sockaddr *)&serveraddr, sizeof(serveraddr));
    success =(err == 0);
    socklen_t addrLen = sizeof(serveraddr);;// Client address length 

    if(success){
        printf(" Successful connection ...\n");
        //getsockname You can correctly obtain the information that you are currently communicating with socketIP Port and other information 
        getsockname(fd, (struct sockaddr *)&addr, &addrLen);
        success = (err == 0);
        //inet_ntoa: Will a IP String converted to Internet standard dot format 
        //ntohs: Convert network byte order to host byte order 

        printf(" Local address :%s, Port number :%d\n",inet_ntoa(addr.sin_addr),ntohs(addr.sin_port));
        // Send a message 
        char buf[1024];
        do{
            printf(" Please enter information :");
 
//                puts(buf);
                scanf("%s",buf);
                send(fd,buf,1024,0);
            }while (strcmp(buf, "exit")!=0);// When the input exit Out of the loop , end 
        }
        else {
            printf(" The connection fails ...\n");
        }
    }
    return 0;
}
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