ftp文件收发代码

server：

#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <string.h>#include <fcntl.h>#include <dirent.h>#include <sys/types.h>          /* See NOTES */#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <errno.h>#define N 128typedef struct sockaddr SA;void ProcessList(int connfd){char buf[N];DIR *mydir;struct dirent *myitem;mydir = opendir(".");while ((myitem = readdir(mydir)) != NULL){if ((strcmp(myitem->d_name, ".") == 0) || (strcmp(myitem->d_name, "..") == 0)) continue;strcpy(buf, myitem->d_name);send(connfd, buf, N, 0);}closedir(mydir);return;}void ProcessGet(int connfd, char buf[]){int fd, nbyte;if ((fd = open(buf+1, O_RDONLY)) < 0){fprintf(stderr, "fail to open %s : %s\n", buf+1, strerror(errno));buf[0] = 'N';send(connfd, buf, N, 0);return;}buf[0] = 'Y';send(connfd, buf, N, 0);while ((nbyte = read(fd, buf, N)) > 0){send(connfd, buf, nbyte, 0);}close(fd);return;}void ProcessPut(int connfd, char buf[]){int fd, nbyte;if ((fd = open(buf+1, O_WRONLY|O_CREAT|O_TRUNC, 0666)) < 0){printf("fail to create %s on server\n", buf+1);return;}while ((nbyte = recv(connfd, buf, N, 0)) > 0){write(fd, buf, nbyte);}close(fd);return;}int main(int argc, char *argv[]){   int listenfd, connfd;char buf[N];   struct sockaddr_in server_addr;  // XXX:step 1  int socket(int domain, int type, int protocol);   if ((listenfd = socket(PF_INET, SOCK_STREAM, 0)) < 0)   {      fprintf(stderr, "fail to socket : %s\n", strerror(errno));      exit(-1);   }#ifdef _DEBUG_   printf("socket is %d\n", listenfd);#endif    // XXX:step 2  int bind(int sockfd, const struct sockaddr *serv_addr, socklen_t addrlen);   memset(&server_addr, 0, sizeof(server_addr));   server_addr.sin_family = PF_INET;   server_addr.sin_port = htons(8888);   server_addr.sin_addr.s_addr = htonl(INADDR_ANY);if (bind(listenfd, (SA *)&server_addr, sizeof(server_addr)) < 0){perror("fail to bind");exit(-1);}listen(listenfd, 5);     while ( 1 ){if ((connfd = accept(listenfd, NULL, NULL)) < 0){perror("fail to accept");break;}recv(connfd, buf, N, 0);switch (buf[0]){case 'L' :ProcessList(connfd);break;case 'G' :ProcessGet(connfd, buf);break;case 'P' :ProcessPut(connfd, buf);break;}close(connfd);}   return 0;}

client:

#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <string.h>#include <fcntl.h>#include <sys/types.h>          /* See NOTES */#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <errno.h>#define N 128typedef struct sockaddr SA;void PrintHelp(){   printf("help : display help info\n");   printf("list : get file list of server\n");   printf("get  : get <file>\n");   printf("put  : put <file>\n");printf("quit : quit the client\n");return;}void ProcessList(struct sockaddr_in server_addr){ int sockfd, nbyte;char buf[N];if ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) < 0){ printf("fail to list\n");return;}if (connect(sockfd, (SA *)&server_addr, sizeof(server_addr)) < 0)   {      printf("fail to connect server\n");goto ERROR_1;   }strcpy(buf, "L");send(sockfd, buf, N, 0);   while ((nbyte = recv(sockfd, buf, N, 0)) != 0){printf("%s\n", buf);}ERROR_1:close(sockfd);   return;}void ProcessGet(struct sockaddr_in server_addr, char command[]){int sockfd, nbyte, fd;   char buf[N];if ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) < 0){   printf("fail to get\n");return;}if (connect(sockfd, (SA *)&server_addr, sizeof(server_addr)) < 0)   {      printf("fail to connect server\n");goto ERROR_2;          }sprintf(buf, "G%s", command+4);send(sockfd, buf, N, 0);   recv(sockfd, buf, N, 0);if (buf[0] == 'N') // no such file{printf("No such file on server\n");goto ERROR_2;}   if ((fd = open(command+4, O_WRONLY|O_CREAT|O_TRUNC, 0666)) < 0){   printf("fail to create local file %s\n", command+4);goto ERROR_2;} while ((nbyte = recv(sockfd, buf, N, 0)) > 0){write(fd, buf, nbyte);}close(fd);ERROR_2:close(sockfd);return;}void ProcessPut(struct sockaddr_in server_addr, char command[]){int sockfd, fd, nbyte;char buf[N];   if ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) < 0){   printf("fail to get\n");return;}if (connect(sockfd, (SA *)&server_addr, sizeof(server_addr)) < 0)   {      printf("fail to connect server\n");goto ERROR_3;          }   if ((fd = open(command+4, O_RDONLY)) < 0){printf("fail to open %s\n", command+4);goto ERROR_3;}  sprintf(buf, "P%s", command+4);send(sockfd, buf, N, 0);while ((nbyte = read(fd, buf, N)) > 0){send(sockfd, buf, nbyte, 0);}close(fd);ERROR_3:close(sockfd);return;}int main(int argc, char *argv[]){   int sockfd, fd, nbyte;   char command[32];   struct sockaddr_in server_addr;   if (argc < 3){printf("Usage : %s <server_ip> : <port>\n", argv[0]);exit(-1);}    // XXX:step 1  int socket(int domain, int type, int protocol);   if ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) < 0)   {      fprintf(stderr, "fail to socket : %s\n", strerror(errno));      exit(-1);   }#ifdef _DEBUG_   printf("socket is %d\n", sockfd);#endif    // XXX:step 2  int connect(int sockfd, const struct sockaddr *serv_addr, socklen_t addrlen);   memset(&server_addr, 0, sizeof(server_addr));   server_addr.sin_family = PF_INET;   server_addr.sin_port = htons(atoi(argv[2]));   server_addr.sin_addr.s_addr = inet_addr(argv[1]);   //server_addr.sin_addr.s_addr = htonl(INADDR_ANY);       while ( 1 ){      printf("<client> ");fgets(command, 32, stdin);command[strlen(command)-1] = '\0';  // overwrite the '\n' if (strcmp(command, "help") == 0){   PrintHelp();}else if (strcmp(command, "list") == 0){ProcessList(server_addr);}else if (strncmp(command, "get ", 4) == 0){ProcessGet(server_addr, command);}else if (strncmp(command, "put ", 4) == 0){ProcessPut(server_addr, command);}else if (strcmp(command, "quit") == 0){printf("Bye\n");break;}else{printf("wrong command, 'help' for command list\n");}}   return 0;}