c - 没有从开关盒中出来

Question

我正在编写一个简单的程序来将文件从一个点传输到另一个点。应用程序应显示选项
1.列出文件
2.下载文件
3.上传文件
但是一旦我选择了选项 1，它就会列出目录的内容，我会一一发送文件名，但所有名称都显示在客户端的一行中。不明白为什么..

然后它被困在标记的循环内，一旦recv完成，它应该退出循环，并且它应该再次呈现操作选项。我不确定问题是什么。 这是我的代码..

服务器.c

while(1){
  //receive chosen option to be performed 
  if((rdata = recv(clnt, &x, sizeof(int), 0)) > 0){
    opt = ntohl(x);
    switch(opt){ //switch option and operate
    case 1 : //option 1- transfer contents of the directory
      if((dr = opendir(".")) != NULL){
        while((de = readdir(dr)) != NULL){ //open directory
          sprintf(filename, "%s",de->d_name);
          rdata = send(clnt, filename, strlen(filename), 0); //transfer filenames
        }
      }
      break;
    }

客户端.c

    while(1){ //this loop should continue after performing one option
      printf("1. List available files on the server\n");
      printf("2. Download a file\n");
      printf("3. Upload a file to the server\n");
      scanf("%d", &opt); //enter desired option
      x = htonl(opt);  //convert to network byte order
      if(send(sockfd, &x, sizeof(int), 0) < 0){ //send option
        perror("client: send");
        continue;
      }
      switch(opt){
        case 1 :
/************************************************************************/
          while((rdata = recv(sockfd, filename, sizeof(filename), 0)) > 0){
            filename[rdata] = '\0';
            printf("> %s\n", filename);
          }
/***********************************************************************/
          break;
      }
    }  

Answer 1

至少据我了解，您想要循环直到执行正确的操作(在本例中为 1、2 或 3)。如果是程序应该退出。

int loop = 1;

while(loop){
  loop = 0;
  printf("1. List available files on the server\n");
  printf("2. Download a file\n");
  printf("3. Upload a file to the server\n");
  scanf("%d", &opt);
  x = htonl(opt);
  if(send(sockfd, &x, sizeof(int), 0) < 0){
    perror("client: send");
    continue;
  }
  switch(opt){
    case 1 :
      while((rdata = recv(sockfd, filename, sizeof(filename), 0)) > 0){
        filename[rdata] = '\0';
        printf("> %s\n", filename);
      }
      break;
    default:
      loop = 1;
      break;
  }
}

或者也许您想循环直到选择退出

int loop = 1;

while(loop){
  printf("1. List available files on the server\n");
  printf("2. Download a file\n");
  printf("3. Upload a file to the server\n");
  printf("4. Exir\n");
  scanf("%d", &opt);
  x = htonl(opt);
  if(send(sockfd, &x, sizeof(int), 0) < 0){
    perror("client: send");
    continue;
  }
  switch(opt){
    case 1 :
      while((rdata = recv(sockfd, filename, sizeof(filename), 0)) > 0){
        filename[rdata] = '\0';
        printf("> %s\n", filename);
      }
      break;
    case 4:
      loop = 0;
      break;
    default:
      break;
  }
}