tcp 聊天工具客户端

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/socket.h>
#include <resolv.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#define  MAXBUF 1024

int main(int argc, char *argv[])
{
    int sockfd,len;
    struct sockaddr_in dest;
    char buffer[MAXBUF+1];

    if ( argc != 3 )
    {
        printf("error format, it must be \n\t\t %s ip port \n",argv[0]);
        exit(EXIT_FAILURE);
    }
    if ( (sockfd = socket(AF_INET,SOCK_STREAM,0)) <0)
    {
        printf("socket\n");
        exit(errno);       
    }
    printf("socket created \n");
    bzero(&dest, sizeof(dest));
    dest.sin_family = AF_INET;
    dest.sin_port   = htons(atoi(argv[2]));
    if ( inet_aton(argv[1], (struct in_addr*)&dest.sin_addr.s_addr) == 0)
    {
        perror(argv[1]);
        exit(errno);
    }
    if ( connect(sockfd, (struct sockaddr *)&dest, sizeof(dest)) == -1 )
    {
        perror("connect");
        exit(errno);
    }

    printf("server connected \n");
    while ( 1 )
    {
        bzero(buffer, MAXBUF+1);
        len = recv(sockfd, buffer, MAXBUF, 0);
        if ( len > 0 )
        {
            printf("recv successful :'%s',%d byte recv \n",buffer, len);
        }
        else
        {
            if ( len<0 )
            {
                printf("send failure ,errno code is %d, err msg is  '%s'\n",errno, strerror(errno));
            }
            else
            {
                printf("the other one  close, quit \n");
                break;
            }
        }
        bzero(buffer, MAXBUF+1);
        printf("pls send msg  to send :")
        fgets(buffer, MAXBUF, stdin);
        if ( !strncasecmp(buffer, "quit", 4) )
        {
            printf("I WILL QUIT \n");
            break;
        }
        len = send(sockfd, buffer, strlen(buffer)-1,0);
        if ( len < 0 )
        {
            printf("message '%s'  send failure, errno code is %d, errno msg is '%s' \n",buffer,errno,strerror(errno));
            break;
        }
        else
        {
            printf("message is %s  \t send successful, %d byte send!\n",buffer,len);
        }
        close(sockfd);
        return 0;
    }
}