2月13日 网络编程

搭建一个TCP服务器

#include<stdio.h>

#include<sys/types.h>

#include<sys/socket.h>

#include<arpa/inet.h>

#include<netinet/in.h>

#include<string.h>

#include<unistd.h>

#define ERR_MSG(msg) do{\

fprintf(stderr,"line：_%d_",__LINE__);\

perror(msg);\

}while(0)

#define PORT 9999 //1024~49151

#define IP "192.168.8.99" //ifconfig查看

int main(int argc, const char *argv[])

{

//创建流式套接字-TCP

intsfd = socket(AF_INET,SOCK_STREAM,0);

if(sfd<0){

ERR_MSG("socket");

return-1;

}

printf("sfd=%d\n",sfd);

//填充地址信息结构体，真实地址信息结构体在man 7 IP

//AF-INET ---》man 7 IP

structsockaddr_in sin;

sin.sin_family= AF_INET; //必须填AF_INET;

sin.sin_port =htons(PORT); //网络字节序

sin.sin_addr.s_addr=inet_addr(IP);//本机IP，ifconfig查看

//功能：将IP地址和端口号绑定到制定套接字中；

if(bind(sfd,(structsockaddr*)&sin,sizeof(sin))<0)

{

ERR_MSG("bind");

return-1;

}

printf("bindsuccess _%d_\n",__LINE__);

//功能：将套接字设置为被动监听状态，只负责监听是否有客户端连接成功；

if(listen(sfd,10)<0){

ERR_MSG("listen");

return-1;

}

printf("listensuccess\n");

structsockaddr_in cin; //存储客户端的地址信息

socklen_taddrlen=sizeof(cin);

intnewfd=0;

//功能：阻塞函数，等待客户端链接成功。

//当客户端链接成功后，会从已完成连接的队列头获取一个客户信息

//并生成一个新的文件描述符；

//注意：新生成的文件描述符才是用于通信的文件描述符

newfd=accept(sfd,(structsockaddr*)&cin,&addrlen);

if(newfd<0){

ERR_MSG("accept");

return-1;

}

printf("%s|%dnewfd=%d\n",inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),newfd);

charbuf[128]="";

ssize_tres=0;

while(1)

{

bzero(buf,sizeof(buf));

res=recv(newfd,buf,sizeof(buf),0);

if(res<0){

ERR_MSG("recv");

return-1;

}

elseif(0==res)

{

printf("[%s|%d]newfd=%d客户断开连接\n",

inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),newfd);

break;

}

printf("[%s|%d]newfd=%d:%s\n",

inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),newfd,buf);

//发送-->谁发给我数据，我就发还给谁

strcat(buf,"*-*");

if(send(newfd,buf,sizeof(buf),0)<0)

{

ERR_MSG("send");

return-1;

}

printf("sendsuccess\n");

}

close(newfd);

close(sfd);

return0;

}

搭建一个TCP客户端

#include<stdio.h>

#include<sys/types.h>

#include<sys/socket.h>

#include<arpa/inet.h>

#include<netinet/in.h>

#include<string.h>

#include<unistd.h>

#define ERR_MSG(msg) do{\

fprintf(stderr,"line:__%d__",__LINE__);\

perror(msg);\

}while(0)

#define SER_PORT 9999

#define SER_IP "192.168.8.99"

#define CLI_PORT 7777

#define CLI_IP "192.168.8.99"

int main(int argc, const char *argv[])

{

//创建流式套接字

intcfd=socket(AF_INET,SOCK_STREAM,0);

if(cfd<0)

{

ERR_MSG("socket");

return-1;

}

//绑定地址信息结构体

structsockaddr_in cin;

cin.sin_family= AF_INET;

cin.sin_port = htons(CLI_PORT);//客户端的端口号

cin.sin_addr.s_addr=inet_addr(CLI_IP);//本机IP

if(bind(cfd,(structsockaddr*)&cin,sizeof(cin))<0){

ERR_MSG("bind");

return-1;

}

printf("clientbind success\n");

//填充要连接的服务器的IP和端口，根据地址族制定

structsockaddr_in sin;

sin.sin_family= AF_INET;

sin.sin_port=htons(SER_PORT);

sin.sin_addr.s_addr=inet_addr(SER_IP);

//连接服务器

if(connect(cfd,(structsockaddr*)&sin,sizeof(sin))<0){

ERR_MSG("connect");

return-1;

}

charbuf[128];

ssize_tres=0;

while(1){

bzero(buf,sizeof(buf));

//发送数据给服务器，服务器收多少，就发送多少

printf("请输入》》》");

fgets(buf,sizeof(buf),stdin);

buf[strlen(buf)-1]=0;

if(send(cfd,buf,sizeof(buf),0)<0){

ERR_MSG("send");

return-1;

}

printf("sendsuccess\n");

bzero(buf,sizeof(buf));

res=recv(cfd,buf,sizeof(buf),0);

if(res<0){

ERR_MSG("recv");

return -1;

}

elseif(0==res){

printf("服务器关闭\n");

break;

}

printf("%s\n",buf);

}

close(cfd);

return0;

}

3.搭建一个udp服务器

#include<stdio.h>

#include<sys/types.h>

#include<sys/socket.h>

#include<netinet/in.h>

#include<arpa/inet.h>

#include<unistd.h>

#include<string.h>

#define PORT 3333

#define IP "192.168.8.99"

int main(int argc, const char *argv[])

{

intsfd=socket(AF_INET,SOCK_DGRAM,0);

if(sfd<0){

perror("socket");

return-1;

}

structsockaddr_in sin;

sin.sin_family =AF_INET;

sin.sin_port =htons(PORT);

sin.sin_addr.s_addr = inet_addr(IP);

//绑定服务器的地址信息结构体

if(bind(sfd,(structsockaddr*)&sin,sizeof(sin))<0)

{

perror("bind");

return-1;

}

printf("serverbind success\n");

charbuf[128]="";

ssize_tres=0;

structsockaddr_in cin;

socklen_taddrlen=sizeof(cin);

while(1)

{

bzero(buf,sizeof(buf));

//接受客户端发来的消息

res=recvfrom(sfd,buf,sizeof(buf),0,(structsockaddr*)&cin,&addrlen);

if(res<0)

{

perror("recvfrom");

return-1;

}

printf("[%s:%d]:%s\n",inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),buf);

//将数据发送给客户端-->谁发给我，我发还给谁

strcat(buf,"*-*");

if(sendto(sfd,buf,sizeof(buf),0,(structsockaddr*)&cin,sizeof(cin))<0){

perror("sendto");

return-1;

}

printf("sendtosuccess\n");

}

//关闭套接字文件描述符

close(sfd);

return0;

}

4.搭建一个udp客户端

#include<stdio.h>

#include<sys/types.h>

#include<sys/socket.h>

#include<netinet/in.h>

#include<arpa/inet.h>

#include<unistd.h>

#include<string.h>

#define PORT 3333

#define IP "192.168.8.99"

//创建报式套接字

int main(int argc, const char *argv[])

{

intsfd=socket(AF_INET,SOCK_DGRAM,0);

if(sfd<0){

perror("socket");

return-1;

}

//服务器的地址信息结构体，供给线面sengto函数

structsockaddr_in sin;

sin.sin_family =AF_INET;

sin.sin_port =htons(PORT);

sin.sin_addr.s_addr = inet_addr(IP);

/*绑定客户端的地址信息结构体

if(bind(sfd,(structsockaddr*)&sin,sizeof(sin))<0)

{

perror("bind");

return-1;

}

printf("serverbind success\n");

*/

charbuf[128]="";

ssize_tres=0;

structsockaddr_in rcvaddr;

socklen_taddrlen=sizeof(rcvaddr);

while(1)

{

//将数据7发送给服务器

bzero(buf,sizeof(buf));

printf("请输入");

fgets(buf,sizeof(buf),stdin);

buf[strlen(buf)-1]=0;

if(sendto(sfd,buf,sizeof(buf),0,(structsockaddr*)&sin,sizeof(sin))<0){

perror("sendto");

return-1;

}

printf("sendtosuccess\n");

bzero(buf,sizeof(buf));

//接受服务器发来的消息

res=recvfrom(sfd,buf,sizeof(buf),0,(structsockaddr*)&rcvaddr,&addrlen);

if(res<0)

{

perror("recvfrom");

return-1;

}

printf("[%s:%d]:%s\n",inet_ntoa(rcvaddr.sin_addr),ntohs(rcvaddr.sin_port),buf);

}

//关闭套接字文件描述符

close(sfd);

return0;

}

5.tftp通信客户端搭建

#include<stdio.h>

#include<sys/types.h>

#include<sys/socket.h>

#include<netinet/in.h>

#include<arpa/inet.h>

#include<unistd.h>

#include<string.h>

#define PORT 69

#define IP "192.168.8.244"

int main(int argc, const char *argv[])

{

intsfd=socket(AF_INET,SOCK_DGRAM,0);

if(sfd<0){

perror("socket");

return-1;

}

structsockaddr_in sin;

sin.sin_family =AF_INET;

sin.sin_port =htons(PORT);

sin.sin_addr.s_addr = inet_addr(IP);

//绑定客户端的地址信息结构体

if(bind(sfd,(structsockaddr*)&sin,sizeof(sin))<0)

{

perror("bind");

return-1;

}

charbuf[516]="";

short*p1=(short*)buf;

*p1=htons(1);

char*p2=buf+2;

strcpy(p2,"1.png");

char*p3=p2+strlen(p2);

*p3=0;

char*p4=p3+1;

strcpy(p4,"octet");

char*p5=p4+strlen(p4);

*p5=0;

intsize=2+strlen(p2)+1+strlen(p4)+1;

printf("p2=%sp4=%s size=%d\n",p2,p4,size);

if(sendto(sfd,buf,size,0,(structsockaddr*)&sin,sizeof(sin))<0)

{

perror("sendto");

return-1;

}

printf("sendtosuccess\n");

intres=0;

charbook[516]="";

while(1){

res=recvfrom(sfd,book,sizeof(book),0,NULL,NULL);

char

}

return0;

}