8 replies to this topic

[dublindan]

What would be the easiest way of listing the filenames of all files (either of a particular extension, or ALL files regardless of file type) in a directory and storing this list in list of some sort (std::vector or something simular), using C++? I want to be able to do this on both windows and linux, so if someone could tell me a method for both systems, that would be great. (I'll then use conditional compilation to do the rest). Thanks in advance.

[qesbit]

boost::filesystem is interesting.

[dublindan]

Thanks, I'll take a look at it, though I was kinda hoping to do it with standard windows.h and unix equivelent, rather than a new API..

[Zahlman]

Are you *really* bent on using C++ for this? :(

from os import walk, sep # routine to walk a directory tree, and the platform's separator for filenames.
def files_with_extension(in_folder, ext = ""):
  # For each folder entry in the walk() output, pair up the folder name with
  # each file matching the criterion, creating a list. Then collect those into
  # a list of lists, and flatten it.
  return sum([[x[0] + sep + y for y in x[2] if y.endswith(ext)]
              for x in walk(in_folder)], [])

[dublindan]

Yes, I need/want to use C++.
Its for a plugin system for my game engine. I want it to search for .dll/.so (depending on platform) files in a "plugin" directory and either load them, or list them for optional loading later.
I really want to just have to dump a new DLL into a directory to add its functionality to my engine, while right now I have to state its name someplace too..

[Anon Mike]

There is no standard api to do this in C++. You either have to use a third-party library (like boost) or OS-specific API's.

In Windows you use FindFirstFile/FindNextFile/FindClose. I don't know how you do in in Linux.

[dublindan]

Thanks for the reply.
I don't mind using OS specific API's as long as I can achieve the same result on all platforms.

Ok, I managed to find how to do this.
Yes, I did it with FindFirstFile (etc).
Here is my resulting code (the linux code is untested though):

#ifdef WIN32
#include <windows.h>
#else
#include <dirent.h>
#endif

void GetFileList (std::vector<std::string>& list, std::string dir, std::string extension)
{
#ifdef WIN32
	WIN32_FIND_DATA findData;
	HANDLE fileHandle;
	int flag = 1;
	std::string search ("*.");
	if (dir == "") dir = ".";
	dir += "/";
	search = dir + search + extension;
	// SetCurrentDirectory(dir.c_str());
	fileHandle = FindFirstFile(search.c_str(), &findData);
	if (fileHandle == INVALID_HANDLE_VALUE) return;
	while (flag)
	{
		list.push_back(findData.cFileName);
		flag = FindNextFile(fileHandle, &findData);
	}
	FindClose(fileHandle);

#else

	std::string search(".");
	search += extension;
	DIR* dir = opendir(dir.c_str());
	struct dirent* entry;
	std::string temp;

	while ((entry = readdir(dir)) != NULL)
	{
		temp = entry->d_name;
		if (temp.substr(, search.size()) == search)
		{
			list.push_back(temp);
		}
	}
	closedir(dir);
#endif
}

If someone could test this on linux, Id really appreciate it as I am unable to do so myself right now and Id like to know if it works before implementing it.

[Boder]

Alright, got it working in SUSE Linux. Made a few changes to get it to work. This should do the trick.

#ifdef WIN32

#include <windows.h>

#else

#include <dirent.h>

#endif



#include <iostream>

#include <vector>

#include <string>

using namespace std;



void GetFileList (std::vector<std::string>& list, std::string dir, std::string extension)

{

#ifdef WIN32

	WIN32_FIND_DATA findData;

	HANDLE fileHandle;

	int flag = 1;

	std::string search ("*.");

	if (dir == "") dir = ".";

	dir += "/";

	search = dir + search + extension;

	// SetCurrentDirectory(dir.c_str());

	fileHandle = FindFirstFile(search.c_str(), &findData);

	if (fileHandle == INVALID_HANDLE_VALUE) return;

	while (flag)

	{

		list.push_back(findData.cFileName);

		flag = FindNextFile(fileHandle, &findData);

	}

	FindClose(fileHandle);



#else



	std::string search(".");

	search += extension;

	DIR* directory = opendir(dir.c_str()); // *change

	struct dirent* entry;

	std::string temp;



	while ((entry = readdir(directory)) != NULL) // see above change

	{

		temp = entry->d_name;

		if (temp.find(search, 0) != string::npos) // *change

		{

			list.push_back(temp);

		}

	}

	closedir(directory); // change, see first change

#endif

}



int main(int argc, char** argv)

{

	vector<string> list;



	GetFileList(list, ".", "txt");



	for(int i=0; i < list.size(); i++)

		cout << list[i] << endl;



	return 0;

}

[dublindan]

Thanks!

Heh, stupid mistake! I never noticed it because the unic code never ran when I tested it, DOH!

Thanks again.