流协议与粘包(二)

read,write与recv,send
readline实现
用readline实现回射客户、服务器
getsockname ,getpeername
gethostname,gethostbyname,gethostbyaddr

基于readline的回射客户/服务器

服务端

  1 #include <stdio.h>
  2 #include <errno.h>
  3 #include <string.h>
  4 #include <stdlib.h>
  5 #include <unistd.h>
  6 #include <sys/types.h>
  7 #include <sys/socket.h>
  8 #include <netinet/in.h>
  9 #include <arpa/inet.h>
 10 
 11 #define ERR_EXIT(m)
 12     do{
 13         perror(m);
 14         exit(EXIT_FAILURE);
 15     }while(0)
 16 
 17 
 18 ssize_t readn(int fd, void* buf,size_t count)
 19 {
 20     size_t nleft = count;
 21     ssize_t nread;
 22     char *bufp = (char*)buf;
 23     
 24     while(nleft > 0)
 25     {
 26         if((nread = read(fd,bufp,nleft)) < 0)
 27         {
 28             if(errno == EINTR)
 29                 continue;
 30             return -1;
 31         }
 32         else if(nread == 0)
 33         {
 34             return count-nleft;
 35         }
 36         
 37         bufp += nread;
 38         nleft -= nread;
 39     }
 40     return count;
 41 }
 42 
 43 ssize_t writen(int fd, void* buf,size_t count)
 44 {
 45     size_t nleft = count;
 46     ssize_t nwrite;
 47     char *bufp = (char*)buf;
 48     
 49     while(nleft > 0)
 50     {
 51         if((nwrite = write(fd,bufp,nleft)) < 0)
 52         {
 53             if (errno = EINTR)
 54                 continue;
 55             return -1;
 56         }
 57         else if(nwrite == 0)
 58             continue;
 59         bufp += nwrite;
 60         nleft -= nwrite;
 61     }    
 62     return count;
 63 }
 64 
 65 ssize_t recv_peek(int fd, void* buf,size_t count)
 66 {
 67     while(1)
 68     {
 69         int ret = recv(fd,buf,count,MSG_PEEK);
 70         if(ret == -1 && errno == EINTR)
 71             continue;
 72         return ret;
 73     }
 74 }
 75 
 76 ssize_t readline(int sockfd,void *buf,size_t maxline)
 77 {
 78     int ret;
 79     int nread;
 80     char *bufp= buf;
 81     int nleft =maxline;
 82     while(1)
 83     {
 84         ret = recv_peek(sockfd,bufp,nleft);
 85         if(ret < 0)
 86             return ret;
 87         else if(ret == 0)
 88             return ret;
 89         nread = ret;
 90         int i;
 91         for(i = 0; i < nread; i++)
 92         {
 93             if(bufp[i] == '
')
 94             {
 95                 ret = readn(sockfd,bufp, i+1);
 96                 if(ret != i+1)
 97                     exit(EXIT_FAILURE);
 98                 return ret;
 99             }
100         }
101         if(nread > nleft)
102             exit(EXIT_FAILURE);
103         nleft -= nread;
104         ret = readn(sockfd,bufp,nread);
105         if(ret != nread)
106             exit(EXIT_FAILURE);
107         bufp += nread;
108     } 
109     return -1;
110 }
111 
112 void do_service(int conn)
113 {
114     char recvbuf[1024];
115     int n;
116     while(1)
117     {
118         memset(recvbuf,0,sizeof(recvbuf));
119         int ret = readline(conn,recvbuf,1024);
120         if(ret == -1)
121             ERR_EXIT("read");
122         if(ret == 0)
123         {
124             printf("clien close");
125             break;
126         }
127                 
128         fputs(recvbuf,stdout);
129         writen(conn,recvbuf,strlen(recvbuf));
130     }
131 }
132 
133 int main(void)
134 {
135     int listenfd;
136     if((listenfd = socket(AF_INET,SOCK_STREAM,0)) < 0)
137         ERR_EXIT("socket");
138 
139     struct sockaddr_in servaddr;
140     memset(&servaddr, 0, sizeof(servaddr));
141     servaddr.sin_family = AF_INET;
142     servaddr.sin_port = htons(5188);
143     servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
144 
145     int on;
146     if(setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
147         ERR_EXIT("setsockopt");
148     if(bind(listenfd,(struct sockaddr*)&servaddr,sizeof(servaddr)) < 0)
149         ERR_EXIT("bind");
150     if(listen(listenfd,SOMAXCONN) < 0)
151         ERR_EXIT("listen");
152     struct sockaddr_in peeraddr;
153     socklen_t peerlen = sizeof(peeraddr);
154     int conn;
155 
156     pid_t pid;
157     while(1)
158     {
159         if((conn = accept(listenfd,(struct sockaddr*)&peeraddr,&peerlen)) < 0)
160             ERR_EXIT("accept");
161         printf("ip=%s,port=%d	
",inet_ntoa(peeraddr.sin_addr),ntohs(peeraddr.sin_port));
162 
163         pid = fork();
164         if(pid == -1)
165             ERR_EXIT("fork");
166         if(pid == 0)
167         {
168             close(listenfd);
169             do_service(conn);
170             exit(EXIT_SUCCESS);
171         }
172         else
173             close(conn);
174     }
175     return 0;    
176 }

View Code

客户端

  1 #include <stdio.h>
  2 #include <errno.h>
  3 #include <string.h>
  4 #include <stdlib.h>
  5 #include <unistd.h>
  6 #include <sys/types.h>
  7 #include <sys/socket.h>
  8 #include <netinet/in.h>
  9 #include <arpa/inet.h>
 10 
 11 #define ERR_EXIT(m)
 12     do{
 13         perror(m);
 14         exit(EXIT_FAILURE);
 15     }while(0)
 16 
 17 ssize_t readn(int fd, void* buf,size_t count)
 18 {
 19     size_t nleft = count;
 20     ssize_t nread;
 21     char *bufp = (char*)buf;
 22     
 23     while(nleft > 0)
 24     {
 25         if((nread = read(fd,bufp,nleft)) < 0)
 26         {
 27             if(errno == EINTR)
 28                 continue;
 29             return -1;
 30         }
 31         else if(nread == 0)
 32         {
 33             return count-nleft;
 34         }
 35         
 36         bufp += nread;
 37         nleft -= nread;
 38     }
 39     return count;
 40 }
 41 
 42 ssize_t writen(int fd, void* buf,size_t count)
 43 {
 44     size_t nleft = count;
 45     ssize_t nwrite;
 46     char *bufp = (char*)buf;
 47     
 48     while(nleft > 0)
 49     {
 50         if((nwrite = write(fd,bufp,nleft)) < 0)
 51         {
 52             if (errno = EINTR)
 53                 continue;
 54             return -1;
 55         }
 56         else if(nwrite == 0)
 57             continue;
 58         bufp += nwrite;
 59         nleft -= nwrite;
 60     }    
 61     return count;
 62 }
 63 
 64 size_t recv_peek(int fd, void* buf,size_t count)
 65 {
 66         while(1)
 67         {
 68                 int ret = recv(fd,buf,count,MSG_PEEK);
 69                 if(ret == -1 && errno == EINTR)
 70                         continue;
 71                 return ret;
 72         }
 73 }
 74 
 75 ssize_t readline(int sockfd,void *buf,size_t maxline)
 76 {
 77         int ret;
 78         int nread;
 79         char *bufp= buf;
 80         int nleft =maxline;
 81         while(1)
 82         {
 83                 ret = recv_peek(sockfd,bufp,nleft);
 84                 if(ret < 0)
 85                         return ret;
 86                 else if(ret == 0)
 87                         return ret;
 88                 nread = ret;
 89                 int i;
 90                 for(i = 0; i < nread; i++)
 91                 {
 92                         if(bufp[i] == '
')
 93                         {   
 94                                 ret = readn(sockfd,bufp, i+1);
 95                                 if(ret != i+1)
 96                                         exit(EXIT_FAILURE);
 97                                 return ret;
 98                         }
 99                 }   
100                 if(nread > nleft)
101                         exit(EXIT_FAILURE);
102                 nleft -= nread;
103                 ret = readn(sockfd,bufp,nread);
104                 if(ret != nread)
105                         exit(EXIT_FAILURE);
106                 bufp += nread;
107         }
108         return -1; 
109 }
110 
111 int main(void)
112 {
113     int sock;
114     if((sock= socket(AF_INET,SOCK_STREAM,0)) < 0)
115         ERR_EXIT("socket");
116 
117     struct sockaddr_in servaddr;
118     memset(&servaddr, 0, sizeof(servaddr));
119     servaddr.sin_family = AF_INET;
120     servaddr.sin_port = htons(5188);
121     servaddr.sin_addr.s_addr = inet_addr("127.0.0.1");
122 
123     if(connect(sock,(struct sockaddr*)&servaddr, sizeof(servaddr)) < 0)
124         ERR_EXIT("connect");
125 
126     struct sockaddr_in localaddr;
127     socklen_t addrlen = sizeof(localaddr);
128     if(getsockname(sock,(struct sockaddr*)&localaddr,&addrlen) < 0)
129         ERR_EXIT("getsockname");
130     printf("ip=%s,port=%d	
",inet_ntoa(localaddr.sin_addr),ntohs(localaddr.sin_port));
131     char sendbuf[1024] = { 0 };
132     char recvbuf[1024] = { 0 };
133     int n;
134     while(fgets(sendbuf,sizeof(sendbuf),stdin) != NULL)
135     {
136         writen(sock,sendbuf,strlen(sendbuf));
137         int ret = readline(sock,recvbuf,sizeof(sendbuf));
138         if(ret == -1)
139             ERR_EXIT("readn");
140         else if(ret ==  0)
141         {
142             printf("client close");
143             break;
144         }
145         
146         fputs(recvbuf,stdout);
147 //        fputs(recvbuf,stdout);
148 
149         memset(sendbuf,0, sizeof(sendbuf));
150         memset(recvbuf,0, sizeof(recvbuf));
151     }
152     close(sock);
153     return 0;    
154 }

View Code

gethostname

 1 #include <stdio.h>
 2 #include <errno.h>
 3 #include <string.h>
 4 #include <stdlib.h>
 5 #include <unistd.h>
 6 #include <sys/types.h>
 7 #include <sys/socket.h>
 8 #include <netinet/in.h>
 9 #include <arpa/inet.h>
10 #include <netdb.h>
11 
12 #define ERR_EXIT(m)
13     do{
14         perror(m);
15         exit(EXIT_FAILURE);
16     }while(0)
17 
18 int getlocalip(char *ip)
19 {
20     char host[100] = { 0 };
21     if(gethostname(host,sizeof(host)) < 0)
22         return -1;
23 
24     struct hostent *hp;
25         if((hp = gethostbyname(host)) == NULL)
26         return -1;
27 
28     strcpy(ip,inet_ntoa(*(struct in_addr*)hp->h_addr_list[0]));
29     return 0;
30 }
31 
32 int main()
33 {
34     char host[100] = { 0 };
35     if(gethostname(host,sizeof(host)) < 0)
36         ERR_EXIT("gethostname");
37     
38     struct hostent *hp;
39     if((hp = gethostbyname(host)) == NULL)
40         ERR_EXIT("gethostbyname");
41     
42     int i = 0;
43     while(hp->h_addr_list[i] != NULL)
44     {
45         printf("%s
",inet_ntoa(*(struct in_addr*)hp->h_addr_list[i]));
46         i++;
47     }
48     char ip[16] = { 0 };
49     getlocalip(ip);
50     printf("localip=%s
",ip);
51     return 0;
52 }

View Code

作者：长风 Email：844064492@qq.com QQ群：607717453 Git：https://github.com/zhaohu19910409Dz 开源项目：https://github.com/OriginMEK/MEK 本文版权归作者和博客园共有，欢迎转载，但未经作者同意必须保留此段声明，且在文章页面明显位置给出原文连接，否则保留追究法律责任的权利. 感谢您的阅读。如果觉得有用的就请各位大神高抬贵手“推荐一下”吧！你的精神支持是博主强大的写作动力。如果觉得我的博客有意思，欢迎点击首页左上角的“+加关注”按钮关注我！

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原文地址：https://www.cnblogs.com/zhaohu/p/8963174.html