Server
#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<assert.h>
#include<stdio.h>
#include<unistd.h>
#include<errno.h>
#include<string.h>
#include<fcntl.h>
#include<stdlib.h>
int main(void){
int ret = 0;
struct sockaddr_in address;
bzero(&address,sizeof(address));
address.sin_family = AF_INET;
address.sin_addr.s_addr = INADDR_ANY;
address.sin_port = htons(9999);
int listenfd = socket(AF_INET,SOCK_STREAM,0);
if(listenfd == -1){
perror("socket");
return -1;
}
ret = bind(listenfd,(struct sockaddr*)&address,sizeof(address));
if(ret == -1){
perror("bind");
return -1;
}
ret = listen(listenfd,5);
if(ret == -1){
perror("listen");
return -1;
}
struct sockaddr_in client_address;
socklen_t client_addrlength = sizeof(client_address);
int connfd = accept(listenfd,(struct sockaddr*)&client_address,&client_addrlength);
if(connfd == -1){
perror("connect");
close(listenfd);
}
char buf[1024];
fd_set read_fds;
fd_set exception_fds;
FD_ZERO(&read_fds);
FD_ZERO(&exception_fds);
while(1){
memset(buf,'\0',sizeof(buf));
FD_SET(connfd,&read_fds);
FD_SET(connfd,&exception_fds);
ret = select(connfd+1,&read_fds,NULL,&exception_fds,NULL);
if(ret == -1){
perror("select");
break;
}
if(FD_ISSET(connfd,&read_fds)){
ret = recv(connfd,buf,sizeof(buf)-1,0);
if(ret == -1){
perror("recv1");
break;
}
printf("get %d bytes of normal data :%s \n",ret,buf);
}else if(FD_ISSET(connfd,&exception_fds)){
//对于同一个连接这里加了else带外数据读不出来
//或许对于不同的连接,带外数据或者读的出来
ret = recv(connfd,buf,sizeof(buf)-1,MSG_OOB);
if(ret == -1){
perror("recv2");
break;
}
printf("get %d bytes of oob data :%s \n",ret,buf);
}
}
close(connfd);
close(listenfd);
return 0;
}
client
#include<stdio.h>
#include<arpa/inet.h>
#include<stdlib.h>
#include<unistd.h>
#include<string.h>
int main(void){
//1.创建套接字
int fd = socket(AF_INET,SOCK_STREAM,0);
if(fd == -1){
perror("socket");
exit(0);
}
//2.连接服务器端
struct sockaddr_in serveraddr;
serveraddr.sin_family = AF_INET;
inet_pton(AF_INET,"192.168.131.138",&serveraddr.sin_addr.s_addr);
serveraddr.sin_port = htons(9999);
int ret = connect(fd,(struct sockaddr*)&serveraddr,sizeof(serveraddr));
if(ret == -1){
perror("connect");
exit(0);
}
//3.通信
const char*oob_data = "abc";
const char*normal_data = "123";
send(fd,normal_data,strlen(normal_data),0);
send(fd,oob_data,strlen(oob_data),MSG_OOB);
send(fd,normal_data,strlen(normal_data),0);
close(fd);
getchar();
return 0;
}
Server program execution result