List files and folders with sizes on Linux

dirworth.c

#define _XOPEN_SOURCE 500
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ftw.h>
#include <sys/stat.h>

static off_t total_size = 0;
static off_t total_symbolic_links = 0;
static off_t total_directories_visited = 0;

// Callback function for nftw()
static int process_entry(const char *fpath, const struct stat *sb,
                          int typeflag, struct FTW *ftwbuf) {
    if (typeflag == FTW_F) {
        // Regular file
        printf("%*s├─ %s (%lld bytes)\n", ftwbuf->level * 2, "",
               fpath + ftwbuf->base, (long long)sb->st_size);
        total_size += sb->st_size;
    } else if (typeflag == FTW_D) {
        // Directory (preorder - before contents)
        if (ftwbuf->level > 0) {
            printf("%*s📁 %s/\n", ftwbuf->level * 2, "",
                   fpath + ftwbuf->base);
        }
    } else if (typeflag == FTW_DNR) {
        // Directory cannot be read
        fprintf(stderr, "Error: Cannot read %s\n", fpath);
    } else if (typeflag == FTW_SL) {
       // Symbolic link.
       ++total_symbolic_links;
    } else if (typeflag == FTW_DP) {
       // Directory, all subdirs have been visited.
       ++total_directories_visited;
    } else {
        fprintf(stderr, "Unknown: typeflag = %d\n", typeflag);
    }
    return 0;  // Continue walking
}

int main(int argc, char *argv[]) {
    if (argc != 2) {
        fprintf(stderr, "Usage: %s <directory_path>\n", argv[0]);
        exit(EXIT_FAILURE);
    }

    const char *dirpath = argv[1];
    total_size = 0;

    printf("Scanning: %s\n\n", dirpath);

    // nftw flags:
    // FTW_PHYS: Don't follow symlinks
    // FTW_DEPTH: Visit files before directories (postorder)
    // 10: Max open file descriptors
    if (nftw(dirpath, process_entry, 10, FTW_PHYS | FTW_DEPTH) == -1) {
        perror("nftw");
        exit(EXIT_FAILURE);
    }

    printf("\n📊 Total size: %lld bytes (%.2f MB)\n",
           (long long)total_size, total_size / (1024.0 * 1024.0));

    printf("\nTotal symbolic links %lld", (long long)total_symbolic_links);
    printf("\nTotal directories visited %lld", (long long)total_directories_visited);
    return 0;
}