1 #include<string.h>
 2 #include <sys/types.h>
 3 #include <sys/socket.h>
 4 #include <sys/time.h>
 5 #include <time.h>
 6 #include <fcntl.h>
 7 #include<netinet/in.h>
 8 #include<arpa/inet.h>
 9 #include <sys/errno.h>
10 #include<iostream>
11 #include<stdlib.h>
12 #include<stdio.h>     //上面这几行可以用 #include "unp.h" 代替
13 using namespace std;
14
15 const int MAXLINE=1024;
16 int main(int argc,char** argv)
17 {
18     int sockfd,connectfd,n;
19     char recvline[MAXLINE+1];
20     char sendline[MAXLINE+1];
21
22     struct sockaddr_in servaddr;
23     if(argc!=2)
24     {
25         cout<<"usage:daytimecli  <IPaddress> "<<endl;
26         exit(0);
27     }
28     sockfd=socket(AF_INET,SOCK_STREAM,0);
29     if(sockfd<0)     //在实际项目的开发中，必须要进行这一步判断，看语句是否执行成功，教材中的包裹函数Socket()就是包含了创建及以下几行的判断过程。
30     {
31         cout<<"socket error"<<endl;
32         exit(0);
33     }
34     memset(&servaddr,0, sizeof(servaddr)); //bzero() ,可以在unp.h中看到该定义
35     servaddr.sin_family=AF_INET;
36     servaddr.sin_port=htons(1300);
37     if(inet_pton(AF_INET,argv[1],&servaddr.sin_addr)<=0)
38     {
39         cout<<"inet_ptons error"<<endl;
40         exit(0);
41     }
42     connectfd = connect(sockfd,(sockaddr*)&servaddr,sizeof(servaddr));
43     if(connectfd < 0)
44     {
45         cout<<"connect error : "<<connectfd<<endl;
46         exit(0);
47     }
48     while((n=read(sockfd,recvline,MAXLINE))>0)
49     {
50         recvline[n]=0;
51         snprintf(sendline,strlen("client send string!\n"),"client send string!\n");
52         write(sockfd,sendline,strlen(sendline)); //相当于winsock的send（）
53         if(fputs(recvline,stdout)==EOF)   //fputs(str,file) 将str输入到文件，该句相当于 cout << recvline;
54         {
55             cout<<"fputs error"<<endl;
56             exit(0);
57         }
58     }
59     if(n<0)
60     {
61       cout<<"read error"<<endl;
62       exit(0);
63     }
64     exit(0);
65 }

 1 #include<string.h>
 2 #include <sys/types.h>
 3 #include <sys/socket.h>
 4 #include <sys/time.h>
 5 #include <time.h>
 6 #include <fcntl.h>
 7 #include<netinet/in.h>
 8 #include<arpa/inet.h>
 9 #include <sys/errno.h>
10 #include<iostream>
11 #include<stdlib.h>
12 #include<stdio.h>
13 #include<errno.h>
14 using namespace std;
15
16 const int MAXLINE = 2048;
17
18 int main(int argc, char **argv)
19 {
20     int listenfd,connfd,bindfd;
21     struct sockaddr_in servaddr;
22     char buff[MAXLINE],recvbuff[MAXLINE];
23     time_t ticks;
24
25     listenfd = socket(AF_INET,SOCK_STREAM,0);
26     if (listenfd < 0)
27     {
28         cout << "listen error : "<<strerror(errno) << endl;
29         exit(0);
30     }
31     memset(&servaddr,0, sizeof(servaddr));
32     servaddr.sin_family = AF_INET;
33     servaddr.sin_port = htons(1300);
34     servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
35
36     bindfd=bind(listenfd, (sockaddr*)&servaddr,sizeof(servaddr));
37     if (bindfd < 0)
38     {
39         cout << "bind error : " << bindfd << endl;
40     }
41     listen(listenfd, 5);
42     while(1) {
43         connfd = accept(listenfd,(sockaddr*)NULL,NULL);
44         ticks = time(NULL);
45         snprintf(buff,sizeof(buff),"%.24s\r\n",ctime(&ticks));
46         cout << "before write,buff : " << buff << endl;
47         write(connfd,buff,strlen(buff));
48         cout << "after write,buff : " << buff << endl;
49         strcat(buff," test for socket!\n" );
50         cout << "after test write,buff : " << buff << endl;
51         write(connfd,buff,strlen(buff));
52         cout << "before read,recvbuff : " << recvbuff << endl;
53         int n=read(connfd,recvbuff,strlen(buff));
54         cout << "after read,recvbuff : " << recvbuff << endl;
55         cout << "read n = "<<n <<"length recvbuff = " << strlen(recvbuff) <<endl;
56         close(connfd);
57     }
58 }