C++ find all files of type in folder?

Question

I am trying to list all the files of a certain type in a folder, so that I can loop through them. This should be simple, surely, but I can't get it. I have found some example using dirent.h, but I need to do this in straight c++.

What is the best way to go about this?

Thanks.

Answer 1

You cannot do this in "straight C++", because C++ does not have a filesystem API yet .

I'd traditionally recommend Boost.Filesystem here, but you allegedly want to "avoid using third party headers if [you] can".

So your best bet is to use POSIX dirent.h , as you have been doing all along. It's about as "non-third party" as you're going to get for the time being.

Answer 2

Something like this? This finds all suid files in folders you specify, but can be modified to find any number of things, or use a regex for the extension if that is what you mean by 'type'.

#include <sys/stat.h>
#include <sys/types.h>
#include <iostream>
#include <string>
#include <sstream>
#include <dirent.h>
#include <vector>


bool is_suid(const char *file)
{
  struct stat results;
  stat(file, &results);
  if (results.st_mode & S_ISUID) return true;
  return false;
}


void help_me(char *me) {
  std::cout
  << "Usage:" << std::endl
  << " " << me << " /bin/ /usr/sbin/ /usr/bin/ /usr/bin/libexec/" << std::endl;
  exit(1);  
}


int main(int argc, char **argv)
{
  if (argc < 2) help_me(argv[0]);
  std::string file_str;
  std::vector<std::string> file_list;
  for (int path_num = 1; path_num != argc; path_num++) {
    const char * path = argv[path_num];
    DIR *the_dir;
    struct dirent *this_dir;
    the_dir = opendir(path);
    if (the_dir != NULL) while (this_dir = readdir(the_dir)) file_list.push_back(std::string(this_dir->d_name));
    std::string name;
    for(int file_num = 0; file_num != file_list.size(); file_num++) {
      name = file_list[file_num];
      std::string path_to_file = std::string(path) + file_list[file_num];
      if (is_suid(path_to_file.c_str()) == true) std::cout << path_to_file << std::endl;
    }
    file_list.clear();
    file_list.shrink_to_fit();
  }
  exit(0);
}