簡單的linux下socket程式設計，分別基於TCP協議實現的簡單程式

linux下socket程式設計可以概括為以下幾個函式的運用：

• socket()
• bind()
• listen()
• connect()
• accept()
• read()
• write()
• close()函式

server端

/*
*   socket簡單程式設計 服務端
 */

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

#define BUFFSIZE 1024

int main(int argc, char *argv[])
{
    int server_sockfd = 0;
    int client_sockfd = 0;
    int len = 0;
    int sin_size = 0;
    struct sockaddr_in server_addr;
    struct sockaddr_in client_addr;
    char buf[BUFFSIZE] = {0};

    bzero(&server_addr, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = INADDR_ANY;
    server_addr.sin_port = htons(8000);

    if((server_sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
    {
        perror("socket error!\n");
        return -1;
    }

    if(bind(server_sockfd, (struct sockaddr *)&server_addr, sizeof(struct sockaddr)) < 0)
    {
        perror("bind error!\n");
        return -1;
    }

    if(listen(server_sockfd, 5) < 0)
    {
        perror("listen error!\n");
        return -1;
    }

    sin_size= sizeof(struct sockaddr_in);

    if((client_sockfd = accept(server_sockfd, (struct sockaddr *)&client_addr, &sin_size)) < 0)
    {
        perror("accept error!\n");
        return -1;
    }

    printf("accept client %s\n",inet_ntoa(client_addr.sin_addr));
    len = send(client_sockfd, "Hello word!\n",30,0);

    while((len = recv(client_sockfd, buf, BUFFSIZE, 0)) >0)
    {
        buf[len] = '\0';
        printf("buf = %s\n",buf);
        if(send(client_sockfd, buf, len, 0) < 0)
        {
            perror("send error!\n");
            return -1;
        }
    }

    close(client_sockfd);
    close(server_sockfd);

    return 0;
}
 

client端

/*
*   socket簡單程式設計 客戶端
 */

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

#define BUFFSIZE 1024

int main(int argc, char *argv[])
{
    int client_sockfd = 0;
    int len = 0;
    struct sockaddr_in server_addr;
    char buf[BUFFSIZE] = {0};
    bzero(&server_addr, sizeof(struct sockaddr_in));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
    server_addr.sin_port = htons(8000);

    if((client_sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
    {
        perror("socket error!\n");
        return -1;
    }

    if(connect(client_sockfd, (struct sockaddr*)&server_addr, sizeof(struct sockaddr)) < 0)
    {
        perror("client error!\n");
        return -1;
    }

    printf("connect success!\n");

    len = recv(client_sockfd, buf, BUFFSIZE, 0);
    buf[len] = '\0';
    printf("client_buf = %s\n",buf);

    while(1)
    {
        printf("Enter string to send:");
        scanf("%s",buf);
        if(!strcmp(buf,"quit"))
        {
            break;
        }

        len = send(client_sockfd, buf, strlen(buf), 0);
        len = recv(client_sockfd, buf, BUFFSIZE, 0);
        buf[len] = '\0';
        printf("received: %s\n",buf);
    }

    close(client_sockfd);

    return 0;
}