readdir.cpp

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

int main(int argc, char** argv) {
  for (int i = 1; i < argc; i++) {
    DIR* dir = opendir(argv[i]);
    if (!dir) {
      fprintf(stderr, "failed top open directory %s\n", argv[i]);
      continue;
    }
    for(;;) {
      dirent* ent = readdir(dir);
      if (ent == NULL) {
        break;
      }
      printf("%s\n", ent->d_name);
    }
    closedir(dir);
  }

  return 0;
}