CODEWITHSUNDEEP
c++windowswinapirecursion
Charles Khunt
Charles Khunt

Reputation: 2505

recursive file search

I'm trying to figure out how to work this thing out .. For some reason, it ends at a certain point.. I'm not very good at recursion and I'm sure the problem lies somewhere there..

Also, even if I checked for cFileName != "..", it still shows up at the end, not sure why but the "." doesn't show up anymore.. 

void find_files( wstring wrkdir )
{
    wstring temp;

    temp = wrkdir + L"\\" + L"*"; 
    fHandle = FindFirstFile( temp.c_str(), &file_data );

    if( fHandle == INVALID_HANDLE_VALUE )
    {
         return;
    }
    else 
    { 
        while( FindNextFile( fHandle, &file_data ) ) 
        {
            if( file_data.dwFileAttributes == FILE_ATTRIBUTE_DIRECTORY &&
                wcscmp(file_data.cFileName, L".") != 0 && 
                        wcscmp(file_data.cFileName, L"..") != 0 )
            {
                find_files( wrkdir + L"\\" + file_data.cFileName  );
            }
            else if( file_data.dwFileAttributes != FILE_ATTRIBUTE_HIDDEN && 
                 file_data.dwFileAttributes != FILE_ATTRIBUTE_SYSTEM  )
            {
                results << wrkdir << "\\" << file_data.cFileName << endl;
            }
        }
    }
}

After changing those, the program doesn't enumerate the remaining files left..

For example, if there is a sub folder named test, it enumerates everything inside test but doesn't finish enumerating the files inside the original directory specified.

Upvotes: 3

Views: 10531

Answers (6)

Alexander Ponomarev
Alexander Ponomarev

Reputation: 2728

Recursive file search with dirent.h

#include <iostream>
#include <dirent.h>
#include <string.h>    

bool isUpDirecory(const char* directory) {
        if (strcmp(directory, "..") == 0 || strcmp(directory, ".") == 0)
            return true;
        else
            return false;
    }

    bool findFile(const std::string& fileName, const std::string& path,
            std::string& resultPath) {
        dirent* entry;
        DIR* dir = opendir(path.c_str());

        if (dir == NULL)
            return false;

        while ((entry = readdir(dir)) != NULL) {
            if (entry->d_type == DT_REG) {
                if (fileName.compare(entry->d_name) == 0) {
                    resultPath = path + "/" + entry->d_name;
                    closedir(dir);
                    return true;
                }
            }
        }

        rewinddir(dir);

        while ((entry = readdir(dir)) != NULL) {
            if (entry->d_type == DT_DIR) {
                if (!isUpDirecory(entry->d_name)) {
                    std::string nextDirectoryPath = path + "/" + entry->d_name;
                    bool result = findFile(fileName, nextDirectoryPath, resultPath);
                    if (result == true) {
                        closedir(dir);
                        return true;
                    }
                }
            }
        }

        closedir(dir);
        return false;
    }

    int main() {
        std::string path;
        bool result = findFile("text.txt", "/home/lamerman/", path);
        std::cout << path << std::endl;
        return 0;
    }

Upvotes: 1

Remy Lebeau
Remy Lebeau

Reputation: 596582

There are still several bugs in your code. Try this instead:

void find_files( wstring wrkdir )
{
    wstring wrkdirtemp = wrkdir;
    if( !wrkdirtemp.empty() && (wrkdirtemp[wrkdirtemp.length()-1] != L'\\')  )
    {
      wrkdirtemp += L"\\";
    }

    WIN32_FIND_DATA file_data = {0};
    HANDLE hFile = FindFirstFile( (wrkdirtemp + L"*").c_str(), &file_data );

    if( hFile == INVALID_HANDLE_VALUE )
    {
         return;
    }

    do
    {
        if( file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY )
        {
            if( (wcscmp(file_data.cFileName, L".") != 0) && 
                (wcscmp(file_data.cFileName, L"..") != 0) )
            {
                find_files( wrkdirtemp + file_data.cFileName );
            }
        }
        else
        {
            if( (file_data.dwFileAttributes & (FILE_ATTRIBUTE_HIDDEN | FILE_ATTRIBUTE_SYSTEM)) == 0 )
            {
                results << wrkdirtemp << file_data.cFileName << endl;
            }
        }
    }
    while( FindNextFile( hFile, &file_data );

    FindClose( hFile );
}

Upvotes: 2

Andrey
Andrey

Reputation: 4356

You still have errors in your code:

  1. you ignore the results of the first search. you call FindFirstFile and handle if it fails. But if it succeeds you do not process already fetched file_data and overwrite it with FindNextFile.
  2. You don't close the search handle. Use FindClose for that.
  3. From your existing code it seems that fHandle is global - it shouldn't. It would break your recursion.

Also I think that you can resolve all the issues in your code by paying more attention to MSDN sample provided in FindFirstFile documentation.

Upvotes: -1

Brian R. Bondy
Brian R. Bondy

Reputation: 347276

From the FindFirstFile documentation:

If the function fails or fails to locate files from the search string in the lpFileName parameter, the return value is INVALID_HANDLE_VALUE and the contents of lpFindFileData are indeterminate.

You should only exit from the one iteration not the whole program:

   if( fHandle == INVALID_HANDLE_VALUE )
   {
     return;
   }

And this may solve your other problem:

else if( file_data.dwFileAttributes != FILE_ATTRIBUTE_HIDDEN && 
   file_data.dwFileAttributes != FILE_ATTRIBUTE_SYSTEM  &&
   wcscmp(file_data.cFileName, L".") != 0 && 
   wcscmp(file_data.cFileName, L"..") != 0
 )
{
    results << wrkdir << "\\" << file_data.cFileName << endl;
}

Also see @fretje's answer as well. It gives another problem that your code has.

Updated new: You need to use fHandle as a local variable as well, not global variable.

Change to: 

 HANDLE fHandle = FindFirstFile( temp.c_str(), &file_data );

Upvotes: 3

sean e
sean e

Reputation: 11925

Also, check out the implementation of the CFileFind MFC class.

Upvotes: 0

fretje
fretje

Reputation: 8372

You are changing the value of your local wrkdir variable:

wrkdir = wrkdir + L"\\" + file_data.cFileName;
find_files( wrkdir );

I think you have to call find_files there like this:

find_files( wrkdir + L"\\" + file_data.cFileName );

and not change the value of wrkdir.

Upvotes: 2

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