Socket_client(TCP)

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

#define PORT 3333     //服务器监听端口号
#define MAXDATASIZE 100    //最大数据传输量

int main(int argc,char *argv[])
{
    int sockfd;
    int recvbytes;
    char buf[MAXDATASIZE];
    struct hostent *host;
    struct sockaddr_in serv_addr;
    if(argc < 2)
    {
        fprintf(stderr,"Please enter the server's hostname!\n");
        exit(1);
    }

    host = gethostbyname(argv[1]);

    if(host == NULL)
    {
        perror("gethostname error!");
        exit(1);
    }

    sockfd = socket(AF_INET,SOCK_STREAM,0);

    if(sockfd == -1)
    {
        perror("socket create error!");
        exit(1);
    }
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(PORT);
    serv_addr.sin_addr = *((struct in_addr *)host->h_addr);
    bzero(&(serv_addr.sin_zero),8);

    int con_ret = connect(sockfd,(struct sockaddr*)&serv_addr,sizeof(struct sockaddr));

    if(con_ret == -1)
    {
        perror("connect error!");
        exit(1);
    }

    recvbytes = recv(sockfd,buf,MAXDATASIZE,0);

    if(recvbytes == -1)
    {
        perror("conncet error!");
        exit(1);
    }
    buf[recvbytes] = '\0';
    printf("receive: %s",buf);
    close(sockfd);

}