tcp client

linux下tcp server，运行文件./tcpserver 8001

#include<stdlib.h>
#include<stdio.h>
#include<string.h>
#include<errno.h>
#include<string.h>
#include<netdb.h>
#include<sys/types.h>
#include<netinet/in.h>
#include<sys/socket.h>
#include<unistd.h>
#include<arpa/inet.h>
//portnumber 8080

int main(int argc ,char *argv[])
{
    int sockfd,new_fd;
    struct sockaddr_in server_addr;
    struct sockaddr_in client_addr;
    int sin_size,iDataNum;
    int portnumber;
//    const char hello[]="Hello cpp, you are success.
";
    char buffer[4096];
    strcpy(buffer, "test111
");

    if(argc!=2)
    {
         fprintf(stderr,"Usage:%s portnumbera
",argv[0]);
         return 0;
    }
    portnumber = atoi(argv[1]);
    if(portnumber < 0)
    {
        fprintf(stderr,"Usage:%s portnumbera
",argv[0]);
        return 0;
    }
    if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1)
    {
        fprintf(stderr,"Socket error:%s
a",strerror(errno));
        return 0;
    }
    bzero(&server_addr,sizeof(struct sockaddr_in));
    server_addr.sin_family=AF_INET;
    server_addr.sin_addr.s_addr=htonl(INADDR_ANY);
    server_addr.sin_port=htons(portnumber);
    if(bind(sockfd,(struct sockaddr *)(&server_addr),sizeof(struct sockaddr))==-1)
    {
        fprintf(stderr,"Bind error:%s
a",strerror(errno));
        return 0;
    }
    if(listen(sockfd,5)==-1)
    {
        fprintf(stderr,"Listen error:%s
a",strerror(errno));
        return 0;
    }
    while(1)
    {
        sin_size=sizeof(struct sockaddr_in);
        if((new_fd = accept(sockfd,(struct sockaddr *)(&client_addr),&sin_size)) == -1)
        {
            fprintf(stderr,"Accept error:%s
a",strerror(errno));
            return 0;
        }
        fprintf(stdout,"Server get connection from %s
",inet_ntoa(client_addr.sin_addr));
        // iDataNum=recv(new_fd,buffer,4096,0);
        // if(iDataNum<0)
        // { 
            // perror("Recv
");
            // exit(1);
        // }
            //printf("Recv data is %s
",buffer);
            send(new_fd, buffer, strlen(buffer), 0);
            // if(write(new_fd,hello,strlen(hello))==-1)
            // {
            //      fprintf(stderr,"write error:%s
",strerror(errno));
            //      return 0;
            // }
        close(new_fd);

    }
    close(sockfd);
   // exit(0);
    return 0;
}

linux 下tcp client, ./tcpclient localhost 8001 或者 ./tcpclient 127.0.0.1 8001

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

int main(int argc,char *argv[])
{
    int sockfd;
    int i = 0;
    int temp = 0;
    char sendbuffer[200];
    char recvbuffer[200];
    char buffer[1024];
    struct sockaddr_in server_addr;
    struct hostent *host;
    int portnumber,nbytes;
    if(argc!=3)
    {
        fprintf(stderr,"Usage :%s hostname portnumbera
",argv[0]);
        exit(1);
    }
    if((host=gethostbyname(argv[1]))==NULL)
    {
        herror("Get host name error
");
        exit(1);
    }
    if((portnumber=atoi(argv[2]))<0)
    {
        fprintf(stderr,"Usage:%s hostname portnumbera
",argv[0]);
        exit(1);
    }

    while (1)
    {
    if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1)
    {
        fprintf(stderr,"Socket Error:%sa
",strerror(errno));
        exit(1);
    }
    bzero(&server_addr,sizeof(server_addr));
    server_addr.sin_family=AF_INET;
    server_addr.sin_port=htons(portnumber);
    server_addr.sin_addr=*((struct in_addr *)host->h_addr);
    

        if(connect(sockfd,(struct sockaddr *)(&server_addr),sizeof(struct sockaddr))==-1)
        {
            fprintf(stderr,"Connect error:%s
",strerror(errno));
            //exit(1);
        }
/*      while(1)
        {
            printf("Please input your word:
");
            scanf("%s",sendbuffer);
            printf("
");
            if(strcmp(sendbuffer,"quit")==0)
                break;
            send(sockfd,sendbuffer,sizeof(sendbuffer),0);
            recv(sockfd,recvbuffer,200,0);
            printf("recv data of my world is :%s
",recvbuffer);
        } */
//        sleep(3);
        if((nbytes = recv(sockfd, buffer, 1024, 0)) == -1)
        {
            fprintf(stderr,"read error:%s
",strerror(errno));
            //exit(1);
        }
        else
        {
//            buffer[nbytes] = '';
//            printf("I have received:%s
", buffer);
            for(i = 0; i < nbytes; i++)
            {
                temp = buffer[i];
                //temp = temp & 0x000000FF;
                printf("%02X ", temp);
            }
            printf("
");
        }
        sleep(3);
        close(sockfd);
    }
    exit(0);
}