如何在C中获取目录的大小？

#include <dirent.h>
#include <sys/stat.h>
#include<stdio.h>

long long get_directory_size(const char *path) {
    long long size = 0;
    struct dirent *entry;
    DIR *dir = opendir(path);

    if (dir == NULL) {
        perror("Failed to open directory");
        return -1;
    }

    while ((entry = readdir(dir)) != NULL) {
        struct stat statbuf;
        const char *entry_path = entry->d_name;
        lstat(entry_path, &statbuf);

        if (S_ISREG(statbuf.st_mode)) {
            size += statbuf.st_size;
        } else if (S_ISDIR(statbuf.st_mode)) {
            if (strcmp(entry_path, ".") != 0 && strcmp(entry_path, "..") != 0) {
                size += get_directory_size(entry_path);
            }
        }
    }

    closedir(dir);
    return size;
}

int main() {
    const char *path = ".";
    long long size = get_directory_size(path);
    printf("Directory size: %lld bytes\n", size);
    return 0;
}