linux下TCP连接的client和server 【转载】

linux下TCP连接的client和server

http://blog.163.com/caipeipei_love@126/blog/static/2596603220101118433940/

基于TCP连接的client和server简单通信

我在看电子书，班主任来了说动手写个client和server的简单通信，只看是不行的，写好了给我看看，真的是一语点中了真理啊：只看不动手，什么时候都不会掌握的！

下午自己就动手写了一个：

主要是基于TCP的三次握手的，面向连接的client和server

tcpserver.c

#include<stdlib.h>
#include<stdio.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>
#define 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;
//    const char hello[]="Hello cpp, you are success.
";
    char buffer[4096];
</span><span style="color: #0000ff;">if</span>(argc!=<span style="color: #800080;">2</span><span style="color: #000000;">)
{
     fprintf(stderr,</span><span style="color: #800000;">"</span><span style="color: #800000;">Usage:%s portnumbera
</span><span style="color: #800000;">"</span>,argv[<span style="color: #800080;">0</span><span style="color: #000000;">]);
     </span><span style="color: #0000ff;">return</span> <span style="color: #800080;">0</span><span style="color: #000000;">;
}

// if((portnumber=atoi(argv[1]))<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,sizeof(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;

}

client.c

#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;

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);

}

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);

}

// if((nbytes=read(sockfd,buffer,1024))==-1)

//{

// fprintf(stderr,"read error:%s
",strerror(errno));

// exit(1);

//  }

// buffer[nbytes]='';

// printf("I have received %s
",buffer);

    close(sockfd);

exit(0);

}

首先要编译tcpserver.c,命令：gcc -g tcpserver.c -o tcpserver

 运行：./tcpserver 8080

然后再编译tcpclient.c，具体命令：gcc -g tcpclient.c -o tcpclient

运行：./tcpclient localhost 8080

查看全文