Viewing directory structure in C++

How exactly can you view the directory structure of a drive? How can you get a listing of files? Basically, I want to know how to write a very simple ls (unix command) or dir (windows command) but how the heck do you do it? I'm sure that there's GUI functions for it, but I want a command line way to do it (I like the command line). Anyone know?

It simple:
For windows applications use the FindFirstFile and FindNextFile functions
For *nix use the opendir and readdir functions

EDIT
these are in C
I changed a bit the windows example, and now uses std::cout
some small examles
WINDOWS
lists all file in c: and subdirectories

Code:

---

#include <string.h>
#include <iostream>
#include <windows.h>

void ListDirRec(const char *s);

int main(){
        std::cout<<"Contents of c:\n";
        ListDirRec("c:\\");
        return 0;
}

void ListDirRec(const char *s){
        char sDir[MAX_PATH]="\0", sTmp[MAX_PATH]="\0";
        WIN32_FIND_DATA theFiles;
        HANDLE hTheFiles;

        ZeroMemory(&theFiles, sizeof(WIN32_FIND_DATA));

        strcpy(sDir, s);
        strcat(sDir, "*");

        hTheFiles = FindFirstFile(sDir, &theFiles);
        if(hTheFiles==INVALID_HANDLE_VALUE) return;

        sDir[strlen(sDir)-1]=0;

        do{
                if( (!strcmp(".", theFiles.cFileName)) || (!strcmp("..", theFiles.cFileName)) )
                        continue;

                if(theFiles.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY){
                        strcpy(sTmp, sDir);
                        strcat(sTmp, theFiles.cFileName);
                        strcat(sTmp, "\\");
                        ListDirRec(sTmp);
                }else{
                        std::cout<<s<<theFiles.cFileName<<std::endl;
                }
        }while(FindNextFile(hTheFiles, &theFiles));

        FindClose(hTheFiles);

        return;
}

---

POSIX
Usage (it the same as ls or dir):
executable [directory]

Code:

---

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

int main(int argc, char *argv[]){
        char dir_name[PATH_MAX];
        DIR *_dir;
        struct dirent *dir_entry;
        struct stat f_nfo;
        int szttl=0;
       
        if(argc==1){               
                getcwd(dir_name, PATH_MAX);
        }else{
                strcpy(dir_name,argv[1]);
        }
       
        _dir = opendir(dir_name);
       
        printf("Contents of '%s'\n", dir_name);
        while( ( dir_entry = readdir(_dir) ) != NULL){
                if(stat(dir_entry->d_name, &f_nfo)){
                        printf("-14%s\n", dir_entry->d_name);                       
                        continue;
                }
                szttl+=f_nfo.st_size;
                printf("%-14s ", dir_entry->d_name);
                if(S_ISDIR(f_nfo.st_mode))
                        printf("    <DIR> ",f_nfo.st_size);
                else
                        printf("%9d ", f_nfo.st_size);
                printf("%s", ctime(&f_nfo.st_ctime));
        }
        printf("\tTotal: %d bytes\n", szttl);
        closedir(_dir);
}

---

And yes to use windows API functions you need always to include windows.h, or try to find the specific header that has a specific function.

Will that display the contents of a given directory? What do I need to use those functions? Just include <windows.h>?