How can I get the list of files in a directory using C or C++?

Question

How can I determine the list of files in a directory from inside my C or C++ code?

I\'m not allowed to execute the ls command and parse the results from

Answer 1

#include
#include 
using namespace std;
char ROOT[]={'.'};

void listfiles(char* path){
    DIR * dirp = opendir(path);
    dirent * dp;
    while ( (dp = readdir(dirp)) !=NULL ) {
         cout << dp->d_name << " size " << dp->d_reclen<1) path=argv[1]; else path=ROOT;

    cout<<"list files in ["<