Recursively find files with a certain extension using FindFirstFile and FindNextFile - c++

Question

I have a working code that returns all files in all sub-directories given a directory with a wild card. For example: "C://*". This works perfectly fine. Now, I was wondering if it is possible to recursively iterate over all files using a certain file extension. For example: "C://*.png", without altering the code. I was looking for sth like: "C://*/../*.png", but I could not find a solution. Are there any wildcard tricks I could use?

Answer 1

And here is an example using FindFirstFile and FindNextFile that can recursively find files having a given extension.
#include "stdafx.h"
#include <Windows.h>
#include <atlpath.h>
#include <list>
#include <iostream>
#ifdef _UNICODE
#define cout wcout
#endif
void FindFiles(
const CString& strRootPath,
const CString& strExt,
std::list<CString>& listFiles,
bool bRecursive = true)
{
CString strFileToFind = strRootPath;
ATLPath::Append(CStrBuf(strFileToFind, MAX_PATH), _T("*.*"));
WIN32_FIND_DATA findData = { 0 };
HANDLE hFileFind = ::FindFirstFile(strFileToFind, &findData);
if (INVALID_HANDLE_VALUE != hFileFind)
{
do
{
CString strFileName = findData.cFileName;
if ((strFileName == _T(".")) || (strFileName == _T("..")))
continue;
CString strFilePath = strRootPath;
ATLPath::Append(CStrBuf(strFilePath, MAX_PATH), strFileName);
if (bRecursive && (ATLPath::IsDirectory(strFilePath)))
{
FindFiles(strFilePath, strExt, listFiles);
}
else
{
CString strFoundExt = ATLPath::FindExtension(strFilePath);
if (! strExt.CompareNoCase(strFoundExt))
istFiles.push_back(strFilePath);
}
} while (::FindNextFile(hFileFind, &findData));
::FindClose(hFileFind);
}
}
int main()
{
std::list<CString> listFiles;
FindFiles(_T("e:\\tests"), _T(".cpp"), listFiles);
for (const auto& strFile : listFiles)
std::cout << strFile.GetString() << std::endl;
return 0;
}
Note: to make things easier, I've used ATL stuff like ATL::CString and ATLPath functions. There is no problem to use them in a Win32 or Console application.

Answer 2

You need to search recursively for each subdirectory. I happen to have some code to do this, the following code might help.
#include <functional>
#include <io.h>
enum enumflags {
ENUM_FILE = 1,
ENUM_DIR,
ENUM_BOTH
};
//return value:
// False means that the searching has been aborted by the callback function.
// It will return true otherwise.
bool enumsubfiles(
const std::wstring &dir_with_back_slant, //for example: L"C:\\", L"E:\\test\\"
const std::wstring &filename, //for example: L"123.txt", L"*.exe", L"123.???"
unsigned int maxdepth, //0 means not searching subdirectories, 1 means maximum depth of subdirectories is 1,
// pass -1 to search all the subdirectories.
enumflags flags, //search files, directories, or both.
std::function<bool(const std::wstring &dir_with_back_slant, _wfinddata_t &attrib)> callback
)
{
_wfinddata_t dat;
size_t hfile;
std::wstring fullname = dir_with_back_slant + filename;
std::wstring tmp;
bool ret = true;
hfile = _wfindfirst(fullname.c_str(), &dat);
if (hfile == -1) goto a;
do {
if (!(wcscmp(L".", dat.name) && wcscmp(L"..", dat.name))) continue;
if (((dat.attrib&_A_SUBDIR) && (!(flags&ENUM_DIR))) || ((!(dat.attrib&_A_SUBDIR)) && (!(flags&ENUM_FILE)))) continue;
ret = callback(dir_with_back_slant, dat);
if (!ret) {
_findclose(hfile);
return ret;
}
} while (_wfindnext(hfile, &dat) == 0);
_findclose(hfile);
a:
if (!maxdepth) return ret;
tmp = dir_with_back_slant + L"*";
hfile = _wfindfirst(tmp.c_str(), &dat);
if (hfile == -1) return ret;
do {
if (!(wcscmp(L".", dat.name) && wcscmp(L"..", dat.name))) continue;
if (!(dat.attrib&_A_SUBDIR)) continue;
tmp = dir_with_back_slant + dat.name + L"\\";
ret = enumsubfiles(tmp, filename, maxdepth - 1, flags, callback);
if (!ret) {
_findclose(hfile);
return ret;
}
} while (_wfindnext(hfile, &dat) == 0);
_findclose(hfile);
return ret;
}
Here is an example of the usage of the function above:
int _tmain(int argc, _TCHAR* argv[])
{
using namespace std;
//the default code page of my console window is 936
setlocale(CP_ACP, ".936");
enumsubfiles(L"C:\\", L"*.exe", 1, ENUM_FILE, [](const std::wstring &dir_with_back_slant, _wfinddata_t &attrib)->bool
{
std::wcout << dir_with_back_slant << attrib.name << '\n';
return true; //return true to continue, return false to abort searching.
});
return 0;
}
And you will get the following output:
C:\OpenSSL-Win64\unins000.exe
C:\putty\PAGEANT.EXE
C:\putty\PLINK.EXE
C:\putty\PSCP.EXE
C:\putty\PSFTP.EXE
C:\putty\PUTTY.EXE
C:\putty\PUTTYGEN.EXE
C:\Windows\ampa.exe
C:\Windows\bfsvc.exe
C:\Windows\explorer.exe
C:\Windows\HelpPane.exe
C:\Windows\hh.exe
C:\Windows\notepad.exe
C:\Windows\regedit.exe
C:\Windows\RtCRU64.exe
C:\Windows\SECOH-QAD.exe
C:\Windows\splwow64.exe
C:\Windows\winhlp32.exe
C:\Windows\write.exe
C:\测试\测试.exe
The maxdepth I passed to the function is 1. Pass -1 to search all the subdirectories.