[001]socket通信--server和client实现迭代的简单例子

server端：

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<unistd.h>
#include<arpa/inet.h>
#include<sys/socket.h>

#define BUFF_SIZE 1024
void error_handling(char* message);

void error_handling(char* message) {
    fputs(message, stderr);
    fputc('
', stderr);
    exit(1);
}

int main(int argc, char **argv)
{
    int serv_sock;
     int clnt_sock;
    char message[BUFF_SIZE];
    int i,str_len;

    //设置一个server地址serv_addr,client地址clnt_addr
    struct sockaddr_in serv_addr;
    struct sockaddr_in clnt_addr;
    socklen_t clnt_addr_size = sizeof(clnt_addr);

    memset(&serv_addr, 0, sizeof(serv_addr));
    memset(&serv_addr, 0, sizeof(serv_addr));

    if (argc != 2) {
        printf("Usage : %s <port>
", argv[0]);
        exit(1);
    }

    //创建用于internet的流协议(TCP)socket
    serv_sock = socket(PF_INET, SOCK_STREAM, 0);
    if (serv_sock == -1) {
        error_handling("socket() error");
    }
 
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    serv_addr.sin_port = htons(atoi(argv[1]));

    //把socket和socket地址结构联系起来
    if( bind(serv_sock,(struct sockaddr*)&serv_addr,sizeof(serv_addr)) == -1) {
        error_handling("bind() error");
    }

    //server_socket用于监听
    if ( listen(serv_sock, 5) == -1) {
        error_handling("lisen() error");
    }

    // 受理连接请求
    for (i = 0; i < 5; i++) {
        clnt_sock = accept(serv_sock,(struct sockaddr*)&clnt_addr,&clnt_addr_size);
        if ( clnt_sock == -1) {
            error_handling("accept() error");
        } else {
            printf("connected client %d 
", i+1);
        }

        while((str_len = read(clnt_sock, message, BUFF_SIZE)) != 0) {
            write(clnt_sock, message, str_len);
        }

        close(clnt_sock);
    }
    close(serv_sock);

    return 0;
}

client端：

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<unistd.h>
#include<arpa/inet.h>
#include<sys/socket.h>

#define BUFF_SIZE 1024
void error_handling(char* message);

void error_handling(char* message) {
    fputs(message, stderr);
    fputc('
', stderr);
    exit(1);
}

int main(int argc, char **argv) {
    int sock;
    struct sockaddr_in serv_addr;
    char message[BUFF_SIZE];
    int str_len;
    memset(&serv_addr, 0, sizeof(serv_addr));

    if (argc != 3)
    {
        printf("Usage: /%s <IP> <Port>
",argv[0]);
        exit(1);
    }

    //创建用于internet的流协议(TCP)socket
    sock = socket(PF_INET, SOCK_STREAM, 0);
    if (sock == -1) {
        error_handling("socket() error");
    }

    //设置一个socket地址结构client_addr,代表客户机internet地址, 端口
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = inet_addr(argv[1]);
    serv_addr.sin_port = htons(atoi(argv[2]));

    //把socket和socket地址结构联系起来
    if( connect(sock,(struct sockaddr*)&serv_addr,sizeof(serv_addr)) == -1) {
        error_handling("connect() error");
    } else {
        printf("connected.......
");
    }

    while(1) {
        fputs("Input mesage(Q to quit) : ", stdout);
        fgets(message, BUFF_SIZE, stdin);

        if (!strcmp(message, "q
") || !strcmp(message, "Q
")) {
            break;
        }

        write(sock, message, strlen(message));
        str_len = read(sock, message, BUFF_SIZE - 1);
        message[str_len] = 0;
        printf("Message from server : %s 
", message);
    }
    close(sock);
    return 0;
}