文件传输协议的简单设计与实现

1、要求：用socket 编程接口编写两个程序，分别为客户程序(client.c)和服务器程序（server.c），该程序应能实现下述命令功能：get：取远方的一个文件put：传给远方一个文件pwd：显示远主当前目录dir：列出远方当前目录cd ：改变远方当前目录？ ：显示你提供的命令quit ：退出返回注意事项：这此命令的具体工作方式（指给出结果的形式）可以参照FTP 的相应命令，有余力的同学可以多实现几个命令。使用Socket进行Client/Server程序设计的一般连接过程是这样的：Server端Listen(监听)某个端口是否有连接请求，Client端向Server端发出Connect(

2、连接)请求，Server端向Client端发回Accept（接受）消息。一个连接就建立起来了。Server端和Client端都可以通过Send，Write等方法与对方通信。 对于一个功能齐全的Socket，都要包含以下基本结构，其工作过程包含以下四个基本的步骤： （1） 创建Socket； （2） 打开连接到Socket的输入/出流； （3） 按照一定的协议对Socket进行读/写操作； （4） 关闭Socket. 下面是源代码：/*client.c*/#include <winsock2.h>#include <stdio.h>#include <stdlib.

3、h>#pragma comment(lib,"ws2_32.lib")#define DEFAULT_PORT        2302#define DEFAULT_BUFFER      2048#define DEFAULT_MESSAGE     "This is a test of the emergency broadcasting system"char szServe

4、rip128,          / Server to connect to      szMessage1024;        / Message to send to severint   iPort     = DEFAULT_PORT; / Port on server to connect to/DWOR

5、D dwCount   = DEFAULT_COUNT; / Number of times to send messageBOOL bSendOnly = FALSE;         / Send data only; don't receiveint dirfun();int getfun();int putfun();int pwdfun();int cdfun();int mdfun();int delfun();int usafun(); void usa

6、ge()    printf("usage: client -p:x -s:IP -n:x -onn");    printf("       -p:x      Remote port to send ton");    printf("       -s:IP  &

7、#160;  Server's IP address or hostnamen");    printf("       -n:x      Number of times to send messagen");    printf("       -o     

8、;   Send messages only; don't receiven");    ExitProcess(1);void ValidateArgs(int argc, char *argv)    int                i;     for(i = 1; i < argc; i+)

9、            if (argvi0 = '-') | (argvi0 = '/')                    switch (tolower(argvi1)         &

10、#160;                  case 'p':        / Remote port                    if (strle

11、n(argvi) > 3)                        iPort = atoi(&argvi3);                    brea

12、k;                case 's':       / Server                    if (strlen(argvi) > 3) 

13、;                       strcpy(szServerip, &argvi3);                    break;  &

14、#160;             case 'n':       / Number of times to send message                    if (strlen(argvi) &g

15、t; 3)                        /dwCount = atol(&argvi3);                    break; 

16、              case 'o':       / Only send message; don't receive                    bSendOnly

17、 = TRUE;                    break;                default:            

18、        usage();                    break;                       

19、 int main(int argc, char *argv)    WSADATA       wsd;    SOCKET        sClient;    char          szBufferDEFAULT_BUFFER;    int

20、60;          ret;    /unsigned int           i;     /int j;    struct sockaddr_in server;    struct hostent    *host = NULL;&

21、#160;    char choice5,choice240;    / Parse the command line and load Winsock    /     argv1="-s:"     strcpy(szServerip, &argv13);    /ValidateArgs(argc, argv);  

22、0; if (WSAStartup(MAKEWORD(2,2), &wsd) != 0)            printf("Failed to load Winsock library!n");        return 1;        /strcpy(szMessage, DEFAULT_MESSAGE);  

23、;  /    / Create the socket, and attempt to connect to the server    /    sClient = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);    if (sClient = INVALID_SOCKET)            printf("s

24、ocket() failed: %dn", WSAGetLastError();        return 1;        server.sin_family = AF_INET;    server.sin_port = htons(iPort);     printf("server.sin_port=%un",server.sin_port); 

25、   server.sin_addr.s_addr = inet_addr(szServerip);   /    / If the supplied server address wasn't in the form    / "aaa.bbb.ccc.ddd" it's a hostname, so try to resolve it    /    if (server.sin_add

26、r.s_addr = INADDR_NONE)            host = gethostbyname(szServerip);        if (host = NULL)                    printf("

27、Unable to resolve server: %sn", szServerip);            return 1;                CopyMemory(&server.sin_addr, host->h_addr_list0,     

28、0;      host->h_length);        if (connect(sClient, (struct sockaddr *)&server,         sizeof(server) = SOCKET_ERROR)            printf("connect()

29、 failed: %dn", WSAGetLastError();        return 1;        /显示接通信息     /     /     /for(j=0;j<2;j+)     /        

30、          ret = recv(sClient, szBuffer, DEFAULT_BUFFER, 0);            if (ret = 0)        / Graceful close          

31、60;     return 0;            else if (ret = SOCKET_ERROR)                            printf(&qu

32、ot;recv() failed: %dn", WSAGetLastError();                return 0;                        szBufferret = '

33、0'              printf("%sn",szBuffer);              if(ret<15)                

34、;                 ret = recv(sClient, szBuffer, DEFAULT_BUFFER, 0);                   if (ret = 0)     &#

35、160;  / Graceful close                       return 0;                   else if (ret = SOCKET_

36、ERROR)                                          /printf("recv() failed: %dn", WSAGetLastEr

37、ror();                       return 0;                          &

38、#160;           szBufferret = '0'                   printf("%sn",szBuffer);           &

39、#160;                /printf("DEFAULT_BUFFER=%dn",DEFAULT_BUFFER);           while(1)                

40、0; puts("-");         printf("ftp> ");         scanf("%s", choice);                     

41、0;     if(strncmp(choice,"dir",3)=0|strncmp(choice,"DIR",2)=0)                       dirfun(sClient);         

42、     continue;                           else if(strncmp(choice,"pwd",3)=0|strncmp(choice,"PWD",3)=0)      

43、60;                           pwdfun(sClient);                   continue;  

44、;                          else if(strncmp(choice,"?",1)=0)                   &#

45、160;             usafun(sClient);                   continue;               

46、0;            else if(strncmp(choice,"quit",4)=0|strncmp(choice,"QUIT",2)=0)                         

47、0;       break;                            scanf("%s", choice2);           

48、   if(strncmp(choice,"get",3)=0|strncmp(choice,"GET",3)=0)                                 getfun(sClient,choice2);

49、                   continue;                            else if(strncmp(choice,&

50、quot;put",3)=0|strncmp(choice,"PUT",3)=0)                                 putfun(sClient,choice2);     &#

51、160;             continue;                             else if(strncmp(choice,"cd",2)=0|strncmp

52、(choice,"CD",2)=0)                                 cdfun(sClient,choice2);          &

53、#160;        continue;                            else if(strncmp(choice,"md",2)=0|strncmp(choice,"MD",2)=0) &

54、#160;                               mdfun(sClient,choice2);                

55、   continue;                            else if(strncmp(choice,"del",3)=0|strncmp(choice,"DEL",3)=0)      

56、0;                          delfun(sClient,choice2);                   continue; 

57、0;                      /else         puts("输入错误，请重新输入");         fflush(stdin);     

58、    fflush(stdin);         printf("n");            printf("n");          closesocket(sClient);     WSACleanup();

59、60;   return 0;int dirfun(SOCKET sClient)         int ret;         char *MSG="dir$"char szBuffer80;         strcpy(szMessage, MSG);     

60、;     ret = send(sClient, szMessage, strlen(szMessage), 0);        if (ret = 0)            return 1;        else if (ret = SOCKET_ERROR)   &

61、#160;                printf("send() failed: %dn", WSAGetLastError();            return 1;             

62、60;  /printf("Send %d bytesn", ret);         /printf("bSendOnly=%dn",bSendOnly);        while(!bSendOnly)                

63、0;     /读取流并显示                       /ret = recv(sClient, szBuffer, 80, 0);              /printf("%s"

64、;,szBuffer);            ret = recv(sClient, szBuffer, 80, 0);            if (ret = 0)        / Graceful close       

65、0;        return 1;            else if (ret = SOCKET_ERROR)                          

66、  printf("recv() failed: %dn", WSAGetLastError();                return 1;                        sz

67、Bufferret = '0'                                                

68、0;  if(strncmp(szBuffer,"226 Close",strlen("226 Close")=0)                                 break;    

69、;                        printf("%s",szBuffer);              if(strncmp(szBuffer,"500 Syntax error",strle

70、n("500 Syntax error")=0)                                 break;            

71、                              return 0;int getfun(SOCKET sClient,char filename40)         int ret;     &#

72、160;   FILE *fpre;         char szBuffer80;          szMessage0='0'         strcat(szMessage, "get$");         /

73、strcat(szMessage, "");         strcat(szMessage,filename);         /printf("MSG4=%cn",szMessage4);                  /szM

74、essage0='g'szMessage1='e'szMessage2='t'         /         /szMessage4='m'szMessage5='e'szMessage6='.'szMessage7='t'        

75、/         /szMessage8='x'szMessage9='t'szMessage10='0'        ret = send(sClient, szMessage, strlen(szMessage)+1, 0);        if (ret = 0)     

76、;       return 1;        else if (ret = SOCKET_ERROR)                    printf("send() failed: %dn", WSAGetLastError();  

77、60;         return 1;                printf("Send %d bytesn", ret);         ret = recv(sClient, szBuffer, 80, 0);    

78、60; /*if (ret = 0)        / Graceful close                break;         else if (ret = SOCKET_ERROR)        

79、              printf("recv() failed: %dn", WSAGetLastError();              break;         */    

80、0;   szBufferret = '0'         printf("%sn",szBuffer);         if(strncmp( szBuffer,"125 Transfering.",strlen("125 Transfering.") )=0)      &#

81、160;                if( (fpre=fopen(filename,"w") = NULL )                            

82、;     printf("open errer");                   return 1;                     

83、0;      printf("bSendOnly=%dn",bSendOnly);              while(!bSendOnly)                      

84、           /读取流并显示                   ret = recv(sClient, szBuffer, 80, 0);              &#

85、160;    if (ret = 0)        / Graceful close                       return 1;          

86、0;        else if (ret = SOCKET_ERROR)                                      

87、0;   printf("recv() failed: %dn", WSAGetLastError();                       return 1;              &#

88、160;                       szBufferret = '0'                        

89、0;             /printf("%s",szBuffer);                                if(strncmp

90、(szBuffer,"226 Transfer",strlen("226 Transfer")=0)                                       &

91、#160;  break;                                      if(strncmp(szBuffer,"500 Syntax error",strlen("50

92、0 Syntax error")=0)                                          break;    

93、0;                                 fprintf(fpre,"%s",szBuffer);            

94、                printf("%sn",szBuffer);              fclose(fpre);              return 0;int pu

95、tfun(SOCKET sClient,char filename40)         int ret;/int i;         FILE *fpse;/char *filename;         /char *MSG="get0me.txt"       

96、           char szBuffer80,temp_buffer80;         /sprintf(szMessage, "get0","te.txt0");         szMessage0='0'      

97、   strcat(szMessage, "put$");         strcat(szMessage,filename);        ret = send(sClient, szMessage, strlen(szMessage)+1, 0);        if (ret = 0)   

98、0;        return 0;        else if (ret = SOCKET_ERROR)                    printf("send() failed: %dn", WSAGetLastError(); &#

99、160;          return 1;                /printf("Send %d bytesn", ret);         /filename="me.txt"    

100、0;    printf("filename=%sn",filename);         if( (fpse=fopen(filename,"r") = NULL )                       printf("

101、;open errer");              return 1;                  else                

102、       printf("The file %s found,ready to transfer.n",filename);              /i=0;              while (fgets(temp_buffer,80,fpse)

103、!=NULL)                                 sprintf(szBuffer,"%s",temp_buffer);           

104、;         send(sClient, szBuffer, 80, 0);                                sprintf(szBuffer, "226 Transfer compl

105、eted. rn");             ret = send(sClient, szBuffer, strlen(szBuffer), 0);          fclose(fpse);         return 0;int pwdfun(SOCKET sClient)  &

106、#160;  int ret;     char *MSG="pwd$"     char szBuffer160;     strcpy(szMessage, MSG);     ret = send(sClient, szMessage, strlen(szMessage), 0);    if (ret = 0)     

107、    return 1;     else if (ret = SOCKET_ERROR)                     printf("send() failed: %dn", WSAGetLastError();       

108、0;    return 1;             printf("Send %d bytesn", ret);     printf("bSendOnly=%dn",bSendOnly);     while(!bSendOnly)         &#

109、160;         /读取流并显示         ret = recv(sClient, szBuffer, 160, 0);         if (ret = 0)        / Graceful close     

110、60;        return 1;         else if (ret = SOCKET_ERROR)                     printf("recv() failed: %dn", WSAGetLastErr

111、or();            return 1;                  szBufferret = '0'         printf("%sn",szBuffer);  &#

112、160;               if(strncmp(szBuffer,"226 Close",strlen("226 Close")=0)                       break; &#

113、160;                if(strncmp(szBuffer,"500 Syntax error",strlen("500 Syntax error")=0)                     &

114、#160; break;                   return 0;int cdfun(SOCKET sClient,char pathname40)     int ret;              szMessage0='0' 

115、0;       strcat(szMessage, "cd$");         strcat(szMessage,pathname);        ret = send(sClient, szMessage, strlen(szMessage)+1, 0);        if (ret =

116、 0)            return 1;        else if (ret = SOCKET_ERROR)                    printf("send() failed: %dn", W

117、SAGetLastError();            return 1;                printf("Send %d bytesn", ret);          return 0;int mdfun(SOCKET sClie

118、nt,char pathname20)     int ret;char szBuffer160;     /char *MSG="md$"     szMessage0='0'     strcat(szMessage, "md$");         /strcat(szMessage, "

119、;");     strcat(szMessage,pathname);     /strcpy(szMessage, MSG);          ret = send(sClient, szMessage, strlen(szMessage)+1, 0);        if (ret = 0)    &

120、#160;       return 1;        else if (ret = SOCKET_ERROR)                    printf("send() failed: %dn", WSAGetLastError();  

121、;          return 1;                printf("Send %d bytesn", ret);        while(!bSendOnly)         

122、             /读取流并显示                     ret = recv(sClient, szBuffer, 80, 0);           

123、if (ret = 0)        / Graceful close                return 1;            else if (ret = SOCKET_ERROR)     

124、0;                      printf("recv() failed: %dn", WSAGetLastError();                return 1;   &

125、#160;                    szBufferret = '0'                          printf("%s&quo

126、t;,szBuffer);                           if(strncmp(szBuffer,"226 Close",strlen("226 Close")=0)          &

127、#160;                      break;                            if(strncm

128、p(szBuffer,"500 Syntax error",strlen("500 Syntax error")=0)                                 break;    

129、60;                                     return 0;int delfun(SOCKET sClient,char name20)     int ret;char szBuffer80

130、;     szMessage0='0'     strcat(szMessage, "del$");      strcat(szMessage,name);     ret = send(sClient, szMessage, strlen(szMessage)+1, 0);    if (ret = 0)    &#

131、160;    return 1;     else if (ret = SOCKET_ERROR)              printf("send() failed: %dn", WSAGetLastError();         return 1;     &

132、#160;    printf("Send %d bytesn", ret);     while(!bSendOnly)             ret = recv(sClient, szBuffer, 80, 0);         if (ret = 0)    

133、0;   / Graceful close              return 1;         else if (ret = SOCKET_ERROR)                  &

134、#160;      printf("recv() failed: %dn", WSAGetLastError();                return 1;                  

135、0;  szBufferret = '0'                       if(strncmp(szBuffer,"del ok",strlen("del ok")=0)            

136、60;               printf("del %s okn",name);                   break;           

137、       printf("%s",szBuffer);         if(strncmp(szBuffer,"500 Syntax error",strlen("500 Syntax error")=0)                

138、60;           break;                                 return 0;int usafun()     puts("-");     puts("get