Network Programming Using Internet Sockets

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Socket网络编程略窥一二.. 网络原理课的课程设计

完全是看这篇文章学的, 貌似有中文版但是我点不进去
就不说两句了, 底层的东西, 全是细节, 非要概括的话可以引用原文第五章的小标题来描述这个过程

5.1. getaddrinfo()—Prepare to launch!
5.2. socket()—Get the File Descriptor!
5.3. bind()—What port am I on?
5.4. connect()—Hey, you!
5.5. listen()—Will somebody please call me?
5.6. accept()—”Thank you for calling port 3490.”
5.7. send() and recv()—Talk to me, baby!
5.8. sendto() and recvfrom()—Talk to me, DGRAM-style
5.9. close() and shutdown()—Get outta my face!

我的代码, 这是linux的, windows有点小不一样, 我不知道 :):
头文件..

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1#include <stdio.h>
2#include <string.h>
3#include <sys/types.h>
4#include <sys/socket.h>
5#include <netdb.h>
6#include <arpa/inet.h>
7#include <stdlib.h>
8 
9#define MYPORT "2222"
10#define BACKLOG 10

用Stream的:

(两个楞大的大括号…)

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1#include "commonheader.h"
2 
3int main() {
4  char function;
5  do {
6    printf("choose to be server(s) or client(c)?\n");
7    scanf("%c",&function);
8  } while(function!='c' && function!='s');
9 
10  if(function=='s') {
11    struct addrinfo hints,*localSv;
12    memset(&hints,0x00,sizeof(hints));
13    hints.ai_family=AF_UNSPEC;
14    hints.ai_socktype=SOCK_STREAM;
15    hints.ai_flags=AI_PASSIVE;
16     
17    int rv;
18    rv=getaddrinfo(NULL,MYPORT,&hints,&localSv);
19    if(rv!=0) {
20      fprintf(stderr,"getaddinfo: %s\n",gai_strerror(rv));
21      return 1;
22    }
23 
24    int sockLs;
25    struct addrinfo *p;
26    for( p=localSv;p;p=p->ai_next) {
27      if( (sockLs=socket(p->ai_family,p->ai_socktype,p->ai_protocol))==-1) {
28    perror("server: socket");
29    continue;
30      }
31     
32      if(bind(sockLs,p->ai_addr, p->ai_addrlen)==-1) {
33    shutdown(sockLs,2);
34    perror("server: bind");
35    continue;
36      }
37 
38      break;
39    }//why linked table?
40 
41    if(p==NULL) {
42      perror("server: failed to bind");
43      return 2;
44    }
45 
46    freeaddrinfo(localSv); //all done with this structure.. so bind() did nothing to struct addrinfo! only to socket(create a socket, and the int is only its number).
47     
48    if (listen(sockLs,BACKLOG)==-1) {
49      perror("listen");
50      exit(1);
51    }
52           
53    struct sockaddr_storage clientSockaddr;
54    int sockCon;
55    printf("Listening..\n");
56    socklen_t clientSockaddrSize=sizeof(clientSockaddr);
57    sockCon=accept(sockLs,(struct sockaddr*)&clientSockaddr,&clientSockaddrSize);
58    printf("Connected.\n");
59    shutdown(sockLs,2);
60     
61    while(1) {
62      char buff[1024];
63      recv(sockCon,buff,sizeof(buff),0);
64      if(strcmp(buff,"exit")==0) {
65    printf("Client exited.\n");
66    break;
67      }
68      printf("%s\n",buff);
69    }
70 
71    shutdown(sockCon,2);
72  }
73 
74  if(function=='c') {
75    printf("Sever IP:\n");
76    char svIp[16];
77    scanf("%s",svIp);
78         
79    struct addrinfo hints,*remoteSv;
80    memset(&hints,0x00,sizeof(hints));
81    hints.ai_family=AF_UNSPEC;
82    hints.ai_socktype=SOCK_STREAM;
83    int rv=getaddrinfo(svIp,MYPORT,&hints,&remoteSv);
84    if(rv!=0) {
85      fprintf(stderr,"getaddinfo: %s\n",gai_strerror(rv));
86      return 1;
87    }
88     
89    int sockCl;
90    struct addrinfo *p;
91    for(p=remoteSv;p;p=p->ai_next) {
92      if( (sockCl=socket(p->ai_family,p->ai_socktype,p->ai_protocol))==-1) {
93    perror("server: socket");
94    continue;
95      }
96       
97      if(connect(sockCl,p->ai_addr,p->ai_addrlen)==-1) {
98    shutdown(sockCl,2);
99    printf("server: connect");
100    continue;
101      }
102 
103      break;
104    }
105 
106    if(p==NULL) {
107      perror("server:failed to setup");
108      return 2;
109    }
110 
111    freeaddrinfo(remoteSv);
112     
113    printf("connected.\n");
114 
115    while(1) {
116      char buff[1024];
117      scanf("%s",buff);
118      send(sockCl,buff,sizeof(buff),0);
119      if(strcmp(buff,"exit")==0) {
120    printf("Exited.\n");
121    break;
122      }
123    }
124    shutdown(sockCl,2);
125  }
126 
127  return 0;
128}

用Datagram的:

view source
print?
1#include "commonheader.h"
2 
3int main() {
4  char function;
5  do {
6    printf("choose to be server(s) or client(c)?\n");
7    scanf("%c",&function);
8  } while(function!='c' && function!='s');
9 
10  if(function=='s') {
11    struct addrinfo hints,*localSv;
12    memset(&hints,0x00,sizeof(hints));
13    hints.ai_family=AF_UNSPEC;
14    hints.ai_socktype=SOCK_DGRAM;
15    hints.ai_flags=AI_PASSIVE;
16     
17    int rv;
18    rv=getaddrinfo(NULL,MYPORT,&hints,&localSv);
19    if(rv!=0) {
20      fprintf(stderr,"getaddinfo: %s\n",gai_strerror(rv));
21      return 1;
22    }
23 
24    int sockLs;
25    struct addrinfo *p;
26    for( p=localSv;p;p=p->ai_next) {
27      if( (sockLs=socket(p->ai_family,p->ai_socktype,p->ai_protocol))==-1) {
28    perror("server: socket");
29    continue;
30      }
31 
32      if(bind(sockLs,p->ai_addr,p->ai_addrlen)==-1) {
33    shutdown(sockLs,2);
34    perror("server: bind");
35      }
36       
37      break;
38    }//why linked table?
39 
40    if(p==NULL) {
41      perror("server: failed to setup");
42      return 2;
43    }
44 
45    freeaddrinfo(localSv); //all done with this structure.. so bind() did nothing to struct addrinfo! only to socket(create a socket, and the int is only its number).
46 
47    /*
48    if (listen(sockLs,BACKLOG)==-1) {
49      perror("listen");
50      exit(1);
51      }
52           
53    struct sockaddr_storage clientSockaddr;
54    int sockCon;
55    printf("Listening..\n");
56    socklen_t clientSockaddrSize=sizeof(clientSockaddr);
57    sockCon=accept(sockLs,(struct sockaddr*)&clientSockaddr,&clientSockaddrSize);
58    printf("Connected.\n");
59    shutdown(sockLs,2);
60    */
61     
62    while(1) {
63      char buff[1024];
64      struct sockaddr from;
65      socklen_t fromlen;
66      recvfrom(sockLs,buff,sizeof(buff),0,
67           &from,&fromlen);
68      if(strcmp(buff,"exit")==0) {
69    printf("Client exited.\n");
70    break;
71      }
72      printf("%s\n",buff);
73    }
74 
75    //    shutdown(sockCon,2);
76  }
77 
78  if(function=='c') {
79    printf("Sever IP:\n");
80    char svIp[100];
81    scanf("%s",svIp);
82         
83    struct addrinfo hints,*remoteSv;
84    memset(&hints,0x00,sizeof(hints));
85    hints.ai_family=AF_UNSPEC;
86    hints.ai_socktype=SOCK_DGRAM;
87    int rv=getaddrinfo(svIp,MYPORT,&hints,&remoteSv);
88    if(rv!=0) {
89      fprintf(stderr,"getaddinfo: %s\n",gai_strerror(rv));
90      return 1;
91    }
92     
93    int sockCl;
94    struct addrinfo *p;
95    for(p=remoteSv;p;p=p->ai_next) {
96      if( (sockCl=socket(p->ai_family,p->ai_socktype,p->ai_protocol))==-1) {
97    perror("server: socket");
98    continue;
99      }
100       
101      /*
102      if(connect(sockCl,p->ai_addr,p->ai_addrlen)==-1) {
103    shutdown(sockCl,2);
104    printf("server: connect");
105    continue;
106      }
107      */
108 
109      break;
110    }
111 
112    if(p==NULL) {
113      perror("server:failed to setup");
114      return 2;
115    }
116 
117    //    freeaddrinfo(remoteSv);
118     
119    //    printf("connected.\n");
120 
121    while(1) {
122      char buff[1024];
123      scanf("%s",buff);
124      sendto(sockCl,buff,sizeof(buff),0,
125         p->ai_addr,p->ai_addrlen);
126      if(strcmp(buff,"exit")==0) {
127    printf("Exited.\n");
128    break;
129      }
130    }
131    shutdown(sockCl,2);
132  }
133 
134  return 0;
135}

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