How do I get a list of files in a directory in C++?

Question

How do you get a list of files within a directory so each can be processed?

Answer 1

You can use the following code for getting all files in a directory.A simple modification in the Andreas Bonini answer to remove the occurance of "." and ".."

CString dirpath="d:\\mydir"
DWORD errVal = ERROR_SUCCESS;
HANDLE dir;
WIN32_FIND_DATA file_data;
CString  file_name,full_file_name;
if ((dir = FindFirstFile((dirname+ "/*"), &file_data)) == INVALID_HANDLE_VALUE)
{
    errVal=ERROR_INVALID_ACCEL_HANDLE;
    return errVal;
}

while (FindNextFile(dir, &file_data)) {
    file_name = file_data.cFileName;
    full_file_name = dirname+ file_name;
    if (strcmp(file_data.cFileName, ".") != 0 && strcmp(file_data.cFileName, "..") != 0)
    {
        m_List.AddTail(full_file_name);
    }
}

Answer 2

Or you do this and then read out the test.txt:

#include <windows.h>

int main() {    
system("dir /b > test.txt");
}

The "/b" means just filenames are returned, no further info.

Answer 3

Here's an example in C on Linux. That's if, you're on Linux and don't mind doing this small bit in ANSI C.

#include <dirent.h>

DIR *dpdf;
struct dirent *epdf;

dpdf = opendir("./");
if (dpdf != NULL){
   while (epdf = readdir(dpdf)){
      printf("Filename: %s",epdf->d_name);
      // std::cout << epdf->d_name << std::endl;
   }
}
closedir(dpdf);

Answer 4

void getFilesList(String filePath,String extension, vector<string> & returnFileName)
{
    WIN32_FIND_DATA fileInfo;
    HANDLE hFind;   
    String  fullPath = filePath + extension;
    hFind = FindFirstFile(fullPath.c_str(), &fileInfo);
    if (hFind == INVALID_HANDLE_VALUE){return;} 
    else {
        return FileName.push_back(filePath+fileInfo.cFileName);
        while (FindNextFile(hFind, &fileInfo) != 0){
            return FileName.push_back(filePath+fileInfo.cFileName);}
        }
 }


 String optfileName ="";        
 String inputFolderPath =""; 
 String extension = "*.jpg*";
 getFilesList(inputFolderPath,extension,filesPaths);
 vector<string>::const_iterator it = filesPaths.begin();
 while( it != filesPaths.end())
 {
    frame = imread(*it);//read file names
            //doyourwork here ( frame );
    sprintf(buf, "%s/Out/%d.jpg", optfileName.c_str(),it->c_str());
    imwrite(buf,frame);   
    it++;
 }

Answer 5

Solving this will require a platform specific solution. Look for opendir() on unix/linux or FindFirstFile() on Windows. Or, there are many libraries that will handle the platform specific part for you.

Answer 6

Here's what I use:

/* Returns a list of files in a directory (except the ones that begin with a dot) */

void GetFilesInDirectory(std::vector<string> &out, const string &directory)
{
#ifdef WINDOWS
    HANDLE dir;
    WIN32_FIND_DATA file_data;

    if ((dir = FindFirstFile((directory + "/*").c_str(), &file_data)) == INVALID_HANDLE_VALUE)
        return; /* No files found */

    do {
        const string file_name = file_data.cFileName;
        const string full_file_name = directory + "/" + file_name;
        const bool is_directory = (file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;

        if (file_name[0] == '.')
            continue;

        if (is_directory)
            continue;

        out.push_back(full_file_name);
    } while (FindNextFile(dir, &file_data));

    FindClose(dir);
#else
    DIR *dir;
    class dirent *ent;
    class stat st;

    dir = opendir(directory);
    while ((ent = readdir(dir)) != NULL) {
        const string file_name = ent->d_name;
        const string full_file_name = directory + "/" + file_name;

        if (file_name[0] == '.')
            continue;

        if (stat(full_file_name.c_str(), &st) == -1)
            continue;

        const bool is_directory = (st.st_mode & S_IFDIR) != 0;

        if (is_directory)
            continue;

        out.push_back(full_file_name);
    }
    closedir(dir);
#endif
} // GetFilesInDirectory