C：遍历目录树中的tree_nodes

Question

我正在构建一个可遍历的目录树。

我绘制的图表将帮助您轻松理解结构：

如何打印当前工作目录（cwd）的子目录（subDir）列表？

例如，我将按以下顺序使用shell命令：

mk_directoryName, cd_directoryName, ls

下面是我对'cd'方法的代码尝试，但它似乎留在根目录并打印所有DIRECTORIES而不仅仅是cwd的子目录：

// *checks whether cwd has a subdirectory named arg
// *if yes, the function returns the corresponding tree node (and become new working directory)
// *if no, prints an error message
// *handle cd and cd ..
struct tree_node *do_cd(struct tree_node *cwd, struct tree_node *root, char *arg) {

    // checks if cwd has a subdirectory named arg
    struct list_node *subDir = cwd -> first_child;

    struct tree_node *parDir = cwd -> parent;
    printf("Making current working directory the parent directory.\n");

    while (subDir != NULL) {
        if (strcmp(subDir -> tree -> string_buffer, arg) == 0) {
            printf("Subdirectory exists: Entering!\n");
            cwd = subDir-> tree;
            printf("Making subdirectory current working directory: name = %s\n", arg);
            printf("Returning current working directory: %s.\n", arg);
            return cwd;
        }
        else if (strcmp(arg, "..") == 0) {
            cwd = parDir;
            printf("Returning to parent directory.\n");
            return cwd;
        }
        else if (strcmp(arg, "") == 0) {
            printf("Returning to root directory.\n");
            return root;
        }
        subDir = subDir-> next;
    }
    printf("Directory does not exist!\n");
    return cwd;
}

打印方法代码尝试：

// prints all children of the directory cwd (not recursively)
void do_ls(struct tree_node *cwd) {
    printf("Listing Directories...\n");
    struct list_node *subDir = cwd -> first_child;
    while (subDir != NULL) {
        printf("%s\n", subDir ->tree -> string_buffer);
        subDir = subDir->next;
    }
}