Unix网络编程---第一次作业

Unix网络编程---第一次作业

要求：

客户端：从命令行读入服务器的IP地址；并连接到服务器；

服务器端： 接受客户的连接请求，并显示客户的IP地址和端口号。

实现代码：

1、客户端程序：my_client.c

#include <sys/socket.h>

#include <sys/types.h>

#include <netinet/in.h>

#include <unistd.h>

#include <stdio.h>

#define UPORT 8088 /*This is the port number used by me */

#define MAXLINE 256

int

main(int argc, char **argv)

{

int sockfd, n;

char recvline[MAXLINE + 1];

struct sockaddr_in servaddr;

if (argc != 2){

perror("usage: a.out <IPaddress>");

exit(-1);

}

if ( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0){

perror("socket error");

exit(-1);

}

bzero(&servaddr, sizeof(servaddr));

servaddr.sin_family = AF_INET;

servaddr.sin_port = htons(UPORT); /* daytime server */

if (inet_pton(AF_INET, argv[1], &servaddr.sin_addr) <= 0){

printf("inet_pton error for %s", argv[1]);

exit(-1);

}

if (connect(sockfd, (struct sockaddr *) &servaddr, sizeof(servaddr)) < 0){

perror("connect error");

exit(-1);

}

while ( (n = read(sockfd, recvline, MAXLINE)) > 0) {

recvline
='\0'; // '\0' ASXII code is 0, so also can use 0;

if (fputs(recvline, stdout) == EOF){

perror("fputs error");

exit(-1);

}

}

if (n < 0)

perror("read error");

exit(0);

}

2、服务端程序：my_server.c

#include <sys/socket.h>

#include <sys/types.h>/*The funcion sizeof,socklen_t need*/

#include <netinet/in.h>/*The funcion sockaddr_in need*/

#include <unistd.h>

#include <arpa/inet.h>/*The funcion inet_ntoa need*/

#include <string.h>/*The funcion strlen need*/

#define UPORT 8088 /*This is the port number used by me */

#define MAXLINE 256

#define LISTENQ 32

int

main(int argc, char **argv)

{

int listenfd, connfd,reuse;

struct sockaddr_in servaddr, cliaddr;

char buff[MAXLINE];

socklen_t addrlen;

listenfd = socket(AF_INET, SOCK_STREAM, 0);

bzero(&servaddr, sizeof(servaddr));

servaddr.sin_family = AF_INET;

servaddr.sin_addr.s_addr = htonl(INADDR_ANY);

servaddr.sin_port = htons(UPORT); /* server port setting */

if( setsockopt(listenfd,SOL_SOCKET,SO_REUSEADDR,&reuse,sizeof(reuse))==-1){

perror("There is an error occured when the program set REUSEADDR symbol");

return -1;

}

if(bind(listenfd, (struct sockaddr *) &servaddr, sizeof(servaddr))==-1){

perror("%s\r\n","bind error");

exit(-1);

}

listen(listenfd, LISTENQ);

addrlen=sizeof(cliaddr);

for ( ; ; ) {

if((connfd = accept(listenfd, (struct sockaddr *) &cliaddr, &addrlen))==-1){

perror("%s\r\n","An error occured while tring to creat a connfd! ");

exit(-1);

}

snprintf(buff, sizeof(buff), "%s %s:%d\r\n","The connection is successful, the ip address and port you are using are",inet_ntoa(cliaddr.sin_addr),cliaddr.sin_port );

printf("the new connection address is:%s:%d\r\n", inet_ntoa(cliaddr.sin_addr), cliaddr.sin_port);

write(connfd, buff, strlen(buff));

//send(connfd,"ok\n",4,0);

close(connfd);

}

}

运行截图

编译：gcc my_client.c -o my_client

gcc my_server.c -o my_server

服务端运行：./my_server

客户端运行：./my_client 192.168.1.119

本实验是在两台虚拟机上操作，服务端ip为192.168.1.119,客户端ip为192.168.1.120

1、客户端：





2、服务端：





总结

1、 注意细节，免走弯路

2、 了解原理，举一反三