ls.cpp

#include <iostream>
#include <dirent.h>

int main(int argc, char* argv[]) {
    const char* directory;
    if (argc < 2) {
        directory = ".";
    } else {
        directory = argv[1];
    }
    DIR* dp = opendir(directory);
    dirent* entry = readdir(dp);
    while (entry != NULL) {
        std::cout << entry->d_name << std::endl;
        entry = readdir(dp);
    }
}