Socket编程：之TCP案例

转载请加上博文引用：http://i.cnblogs.com/EditPosts.aspx?postid=5733248&update=1

服务端：

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

int sockfd;

void do_service(int fd)
{
    long t = time(0);
    char *s = ctime(&t);
    write(fd,s,strlen(s));
}
void out_client(struct sockaddr_in clientaddr)
{
    char buffer[16];
    inet_ntop(AF_INET,&clientaddr.sin_addr.s_addr,buffer,sizeof(clientaddr));
    unsigned short port = ntohs(clientaddr.sin_port);
    printf("client ip:%s (%d)
",buffer,port);
}


int main(int argc,char *argv[])
{
    if(argc < 2)
    {
        fprintf(stderr,"usage: %s port
",argv[0]);
        exit(1);
    }

    //创建套接字
    sockfd = socket(AF_INET,SOCK_STREAM,0);
    if(sockfd < 0)
    {
        fprintf(stderr,"socket: %s
",strerror(errno));
        exit(1);
    }

    //设置IP和端口
    struct sockaddr_in addr;
    memset(&addr,0,sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_port = htons(atoi(argv[1]));
    addr.sin_addr.s_addr = INADDR_ANY; 

    //绑定IP和端口
    int len = sizeof(addr);
    if(bind(sockfd,(struct sockaddr*)&addr,len) < 0)
    {
        fprintf(stderr,"bind: %s
",strerror(errno));
        exit(1);
    }

    //开始听
    if(listen(sockfd,10) < 0)
    {
        fprintf(stderr,"listen: %s
",strerror(errno));
        exit(1);
    }

    while(1)
    {
        struct sockaddr_in clientaddr;
        int c_len = sizeof(clientaddr);
        int fd = accept(sockfd,(struct sockaddr*)&clientaddr,&c_len);
        if(fd < 0)
        {
            fprintf(stderr,"accept: %s
",strerror(errno));
            continue;
        }
        out_client(clientaddr);
        do_service(fd);
        close(fd);
    }
    return 0;
}

编译： 

　　gcc -o server server.c

 运行：

　　./server 6666

客户端：

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

int sockfd;

int main(int argc,char *argv[])
{
    if(argc < 3)
    {
        fprintf(stderr,"usage: %s port
",argv[0]);
        exit(1);
    }

    sockfd = socket(AF_INET,SOCK_STREAM,0);
    if(sockfd < 0)
    {
        fprintf(stderr,"socket:%s
",strerror(errno));
        exit(1);
    }

    struct sockaddr_in sockaddr;
    memset(&sockaddr,0,sizeof(sockaddr));
    sockaddr.sin_family = AF_INET;
    sockaddr.sin_port = htons(atoi(argv[2]));
    inet_pton(AF_INET,argv[1],&sockaddr.sin_addr.s_addr);
    socklen_t len = sizeof(sockaddr);

    if(connect(sockfd,(struct sockaddr*)&sockaddr,len) < 0)
    {
        fprintf(stderr,"connect: %s
",strerror(errno));
        exit(1);
    }
    char buffer[1024];
    memset(buffer,0,sizeof(buffer));
    ssize_t n;
    if((n = read(sockfd,buffer,1024)) < 0)
    {
        fprintf(stderr,"read: %s
",strerror(errno));
        exit(1);
    }
    else
    {
        printf("%s
",buffer);
    }

    return 0;
}

编译： 

　　gcc -o client client.c

 运行：

　　./client 192.168.0.30 6666