如何确定目录或在C Linux中的文件 [英] how to determine directory or file in linux in c

问题描述

我想不打印目录名中只打印文件名。所以，我实现这个功能。

I want to print only file names without printing Directory Names. So, I implement this function

void list_file(char* directory){
  DIR *d;
  struct dirent *dir;
  d = opendir(directory);
  if (d)
  {
    while ((dir = readdir(d)) != NULL)
    {
        printf("%c", dir->d_name[(int)strlen(dir->d_name)]);
        if(dir->d_name[(int)strlen(dir->d_name)-2] != '/')
            printf("%s\n", dir->d_name);
    }

    closedir(d);
  }
}

我检查目录名以/字符结束。所以，我检查，如果有在名称末尾/字符，不打印的名字，但是当我运行的功能，所有的人都在所选目录印刷？

I checked that Directory names ends with '/' character. So, I checked that if there are '/' character at the end of name, don't print that name but when I run the function, all of them is printed in selected directory?

您可以带领我，我怎么能检查目录名的末尾？

Can you lead me that how can I check the end of Directory name?

推荐答案

您要找的是 统计 或其变体之一。具体看 struct stat中的 ST_MODE 字段。你感兴趣的宏 S_ISDIR（X）。

What you are looking for is stat or one of its variants. Specifically look at the st_mode field of struct stat. The macro you are interested in is S_ISDIR(x).

在下面找到您修改code演示你想要什么：

Find below your modified code that demonstrates what you want:

void list_file(char* directory) {
  DIR *d;
  struct dirent *dir;
  int dir_len = strlen(directory);
  char* path = malloc(dir_len + NAME_MAX + 2); // +2, 1 for '/' and 1 for '\0'
  if(path == NULL) {
    fprintf(stderr, "malloc failed\n");
    return;
  }
  strcpy(path, directory);
  if(path[dir_len-1] != '/') {
    path[dir_len] = '/';
    dir_len++;
  }
  d = opendir(directory);
  if (d) {
    while ((dir = readdir(d)) != NULL)
    {
      struct stat buf;
      strcpy(&path[dir_len], dir->d_name);
      if(stat(path, &buf) < 0) {
        fprintf(stderr, "error\n");
      }
      else {if(!S_ISDIR(buf.st_mode)) {
          printf("%s\n", dir->d_name);
        }
      }
    }

    closedir(d);
  }
  free(path);
}

我已删除，因为它是打印字符串的空终止字符的第一个打印。

I have removed your first print as it was printing the null terminating character of the string.

更新：

由于在评论中指出，因为我们正在处理的Linux，你可以使用结构的dirent 的 d_type 字段（这是不 POSIX 的的一部分，但是<一部分HREF =htt​​p://man7.org/linux/man-pages/man3/readdir.3.html相对=nofollow> Linux的）。

As pointed out in the comments since we are dealing with Linux you can use the d_type field in struct dirent (which is not part of POSIX but is part of Linux).

随着中说的code将是如下。

With that said the code would be the following.

void list_file(char* directory){
  DIR *d;
  struct dirent *dir;

  d = opendir(directory);
  if (d) {
    while ((dir = readdir(d)) != NULL)
    {
      struct stat buf;
      if(dir->d_type & DT_DIR) {
         printf("%s\n", dir->d_name);
      }
    }

    closedir(d);
  }
}

这是很多清洁，没有必要的malloc 。

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