Recipe – Recursively find specific files on Windows through C++ lambda expression
Hi Community,
I’m sorry for having been “absent” in the past few months, but I had been commuting (7 months) interstate working on this important project for this department in federal government. I hope to catch up with the blogging and continue contributing as I have done in the past.
Today’s post is about a recipe I recently came up with whilst working on a personal project. The below code snippet allows traversing directory structures and finding specific files in Windows using a C++ lambda expression that’s recursively called.
std::vector<std::wstring> ProjectX::Core::Interop::GetSpecificFiles(std::wstring directoryPath, std::wstring extension) {
std::vector<std::wstring> retval;
auto getFileExt = [&](const std::wstring s) -> std::wstring {
std::wstring retval;
auto nPos = s.rfind('.', s.length());
if (nPos != std::wstring::npos)
retval = s.substr(nPos + 1, s.length() - nPos);
return retval;
};
std::function<void(std::wstring)> fileEnum = [&](std::wstring path) -> void {
WIN32_FIND_DATA fi;
auto searchPattern = std::wstring(path.c_str()).append(L"*.*");
auto found = FindFirstFile(searchPattern.c_str(), &fi);
while (FindNextFile(found, &fi) != 0) {
if (fi.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
if (wcscmp(fi.cFileName, L".") == 0 || wcscmp(fi.cFileName, L"..") == 0)
continue;
else fileEnum(path + fi.cFileName + L"\\"); // Call our lambda here to recurse directory structure
}
else if (getFileExt(fi.cFileName) == extension) {
retval.push_back(path + fi.cFileName);
}
}
};
if (directoryPath.size() > 0 && extension.size() > 0)
fileEnum(directoryPath);
return retval;
}
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Filed under: Microsoft - @ October 2, 2017 9:30 pm
Tags: C++, Microsoft, NTFS, Visual C++, Windows