Linux下的socket實例

寫了一個socket的實例，用於以後測試的時候可以搬過來直接用。

socket_server.cpp

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>

#define PORT 6666 // 端口
#define MAXLINE 4096 // 字符串長度
#define BACKLOG 10 // 偵聽隊列長度

void conn_server(int s)
{
    while (true)
    {
        char buff[MAXLINE];
        int n;
        n = read(s, buff, MAXLINE);
        printf("%d read len %d\n",getpid(), n);
        if (0 > n)
        {
            if (errno == ECONNRESET)
            {
                close(s);
            }
            else
            {
                printf("read socket error: %s(errno: %d)", strerror(errno),
                        errno);
            }
            exit(0);
        }
        else if (0 == n)
        {
            close(s);
            exit(0);
        }
        buff[n] = '\0';
        printf("recv msg from client: %s\n", buff);
    }
}


int main(int argc, char** argv)
{
    int listenfd, connfd;
    struct sockaddr_in servaddr;
    pid_t pid;

    if ((listenfd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
    {
        printf("create socket error: %s(errno: %d)\n", strerror(errno), errno);
        exit(0);
    }
    unsigned value = 1;
    setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &value, sizeof(value));

    bzero(&servaddr, sizeof(servaddr));
    servaddr.sin_family = AF_INET; // 協議族
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY ); // 本地地址
    servaddr.sin_port = htons(PORT); // 服務器端口

    if (bind(listenfd, (struct sockaddr*) &servaddr, sizeof(servaddr)) == -1)
    {
        printf("bind socket error: %s(errno: %d)\n", strerror(errno), errno);
        exit(0);
    }

    if (listen(listenfd, BACKLOG) == -1)
    {
        printf("listen socket error: %s(errno: %d)\n", strerror(errno), errno);
        exit(0);
    }

    printf("======waiting for client's request======\n");
    while (true)
    {
        if ((connfd = accept(listenfd, (struct sockaddr*) NULL, NULL)) == -1)
        {
            printf("accept socket error: %s(errno: %d)", strerror(errno),
                    errno);
            continue;
        }
        pid = fork();
        if(0 == pid)
        {
            close(listenfd);
            conn_server(connfd);
        }
        close(connfd);
    }
    close(listenfd);
}

socket_client.cpp

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>

#define MAXLINE 4096
#define PORT 6666

int main(int argc, char** argv)
{
    int sockfd, n;
    char sendline[MAXLINE];
    struct sockaddr_in servaddr;

    if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
    {
        printf("create socket error: %s(errno: %d)\n", strerror(errno), errno);
        exit(0);
    }

    bzero(&servaddr, sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_port = htons(PORT);
    if (2 == argc)
    {
        if (inet_pton(AF_INET, argv[1], &servaddr.sin_addr) <= 0)
        {
            printf("inet_pton error for %s\n", argv[1]);
            exit(0);
        }
    }
    else
    {
        servaddr.sin_addr.s_addr = htonl(INADDR_ANY );
    }
    if (connect(sockfd, (struct sockaddr*) &servaddr, sizeof(servaddr)) < 0)
    {
        printf("connect error: %s(errno: %d)\n", strerror(errno), errno);
        exit(0);
    }

    while (1)
    {
        printf("send msg to server: \n");
        scanf("%s",sendline);
        if (send(sockfd, sendline, strlen(sendline), 0) < 0)
        {
            printf("send msg error: %s(errno: %d)\n", strerror(errno), errno);
            exit(0);
        }
    }
    close(sockfd);
    exit(0);
}