Why is RemoveDirectory function not deleting the top most folder? - c++

refer: codeguru.com/forum/showthread.php?t=239271
When using the function below to delete folders, all folders, subfolders and files are getting deleted except for the top most folder. Say for the path c:\folder1\folder2 every thing under folder2 is deleted except for folder2.
BOOL DeleteDirectory(const TCHAR* sPath)
{
HANDLE hFind; // file handle
WIN32_FIND_DATA FindFileData;
TCHAR DirPath[MAX_PATH];
TCHAR FileName[MAX_PATH];
_tcscpy(DirPath,sPath);
_tcscat(DirPath,_T("\\"));
_tcscpy(FileName,sPath);
_tcscat(FileName,_T("\\*")); // searching all files
int nRet = 0;
hFind = FindFirstFile(FileName, &FindFileData); // find the first file
if( hFind != INVALID_HANDLE_VALUE )
{
do
{
if( IsDots(FindFileData.cFileName) )
continue; //if not directory continue
_tcscpy(FileName + _tcslen(DirPath), FindFileData.cFileName);
if((FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY))
{
// we have found a directory, recurse
if( !DeleteDirectory(FileName) )
break; // directory couldn't be deleted
}
else
{
if(FindFileData.dwFileAttributes & FILE_ATTRIBUTE_READONLY)
_wchmod(FileName, _S_IWRITE); // change read-only file mode
if( !DeleteFile(FileName) )
break; // file couldn't be deleted
}
}while( FindNextFile(hFind, &FindFileData) );
nRet = FindClose(hFind); // closing file handle
}
return RemoveDirectory(sPath); // remove the empty (maybe not) directory and returns zero when RemoveDirectory function fails
}
Any help in finding the issue is appreciated.
During debugging I noticed that the FindClose function was successfully closing the file handle but GetLastError was returning 32 ("The process cannot access the file because it is being used by another process") However I have no clue after trying with process explorer.

Whilst you can delete a directory this way, it's simpler to let the system do it for you by calling SHFileOperation passing FO_DELETE. Remember that you must double null-terminate the string you pass to this API.

I believe you have to close the file handle before the recursive call. Which means after exiting the recursive call you must again set your your file handle to something appropriate.
SHFileOperation may be a better solution; I am just answering the OP's question of why their code wasn't working as intended.

Refer:http://www.codeguru.com/forum/archive/index.php/t-337897.html
Given below is the code to delete directory using SHFileOperation
bool DeleteDirectory(LPCTSTR lpszDir, bool noRecycleBin = true)
{
int len = _tcslen(lpszDir);
TCHAR* pszFrom = new TCHAR[len+4]; //4 to handle wide char
//_tcscpy(pszFrom, lpszDir); //todo:remove warning//;//convet wchar to char*
wcscpy_s (pszFrom, len+2, lpszDir);
pszFrom[len] = 0;
pszFrom[len+1] = 0;
SHFILEOPSTRUCT fileop;
fileop.hwnd = NULL; // no status display
fileop.wFunc = FO_DELETE; // delete operation
fileop.pFrom = pszFrom; // source file name as double null terminated string
fileop.pTo = NULL; // no destination needed
fileop.fFlags = FOF_NOCONFIRMATION|FOF_SILENT; // do not prompt the user
if(!noRecycleBin)
fileop.fFlags |= FOF_ALLOWUNDO;
fileop.fAnyOperationsAborted = FALSE;
fileop.lpszProgressTitle = NULL;
fileop.hNameMappings = NULL;
int ret = SHFileOperation(&fileop); //SHFileOperation returns zero if successful; otherwise nonzero
delete [] pszFrom;
return (0 == ret);
}

Related

C++ URLDownloadToFile to executable directory in CLR forum

I'm trying to figure out how I can fix two issues that I've been having with the URLDownloadToFile function in C++. The first is that when attempting to download the file in question, the download doesn't actually appear until the CLR C++ window is closed. The second is that as shown on the image below, the resulting file's file name and extension (Which is above the success window) is messed up (Although opening it normally shows that the file downloaded fine, with the name as the exception). If anyone has any suggestions on what I could do to fix these two issues, I'd greatly appreciate it.
For this logic, I'm using:
{
char buffer[MAX_PATH];
GetModuleFileNameA(NULL, buffer, MAX_PATH);
std::string::size_type pos = std::string(buffer).find_last_of("\\/");
return std::string(buffer).substr(0, pos);
}
void StartDownload()
{
HRESULT downloadUpdate;
LPCTSTR downloadUrl = "https://www.google.com/images/branding/googlelogo/1x/googlelogo_color_272x92dp.png", File = "download.png";
string currentDirectory = GetCurrentDirectory();
LPTSTR currentDirectoryLPTSTR = new TCHAR[currentDirectory.size() + 1];
std::string(currentDirectoryLPTSTR).append(File).c_str();
downloadUpdate = URLDownloadToFile(0, downloadUrl, currentDirectoryLPTSTR, 0, 0);
switch (downloadUpdate)
{
case S_OK:
updateSuccess();
break;
case E_OUTOFMEMORY:
updateOOMError();
break;
case INET_E_DOWNLOAD_FAILURE:
updateError();
break;
default:
updateErrorUnknown();
break;
}
}
[STAThread]
int main() {
Application::EnableVisualStyles();
Application::SetCompatibleTextRenderingDefault(false);
Application::Run(gcnew UpdaterGUIProject::UpdaterGUI());
StartDownload();
return 0;
}
LPTSTR currentDirectoryLPTSTR = new TCHAR[currentDirectory.size() + 1]; allocates memory, but does not fill it with any data.
std::string(currentDirectoryLPTSTR) creates a new string object and tries to copy data from currentDirectoryLPTSTR into the string. Which is undefined behavior since currentDirectoryLPTSTR is not a proper null-terminated string. This code does not cause the string object to point at the memory allocated for currentDirectoryLPTSTR, like you clearly think it does.
You are then append()ing File to that string object, not to the contents of currentDirectoryLPTSTR.
And then you throw away the string object you just created, and pass the unfilled currentDirectoryLPTSTR as-is to URLDownloadToFile(). Which is why your output file has a messed-up filename (you are lucky it even shows up in the correct folder at all).
Try this instead:
std::string GetCurrentDirectory()
{
char buffer[MAX_PATH] = {};
DWORD size = GetModuleFileNameA(NULL, buffer, MAX_PATH);
if (size == 0 || size == MAX_PATH) return "";
std::string fileName(buffer, size);
std::string::size_type pos = fileName.find_last_of("\\/");
return fileName.substr(0, pos + 1);
}
void StartDownload()
{
HRESULT downloadUpdate;
LPCSTR downloadUrl = "https://www.google.com/images/branding/googlelogo/1x/googlelogo_color_272x92dp.png", File = "download.png";
string localFile = GetCurrentDirectory() + File;
downloadUpdate = URLDownloadToFileA(0, downloadUrl, localFile.c_str(), 0, 0);
switch (downloadUpdate)
{
case S_OK:
updateSuccess();
break;
case E_OUTOFMEMORY:
updateOOMError();
break;
case INET_E_DOWNLOAD_FAILURE:
updateError();
break;
default:
updateErrorUnknown();
break;
}
}
On a side note, you really shouldn't be downloading files to the same folder that your program is running from. If your program is installed in a folder like C:\Program Files or C:\Program Files (x86), somewhere only admins can write to, then the download will be likely to fail. You should be downloading to a folder that the user has write access to, such as to a subfolder you create under %APPDATA% for your program to use.

How to handle Symbolic Links and Junction while deleting or coping a folder tree

I had task to copy and delete a huge folder using win32 api (C++), I am using the Code Guru recurisive directory deletion code, which works well, but there arises certain question.
RemoveDirectory
Million thanks to Lerooooy Jenkins for pointing it.
The link to CodeGuru for recursive deletes doesn't correctly handle
symbolic links/junctions. Given that a reparse point could point
anywhere (even network drives), you need to be careful when deleting
recursively and only delete the symbolic link/junction and not what it
points at. The correct way to handle this situation is to detect
reparse points (via GetFileAttributes()) and NOT traverse it as a
subdirectory.
So my question is how to actually handle Symbolic Links and Junction while deleting or coping a folder tree.
For the shake of question here is the source code of CodeGuru Directory Deletion
#include <string>
#include <iostream>
#include <windows.h>
#include <conio.h>
int DeleteDirectory(const std::string &refcstrRootDirectory,
bool bDeleteSubdirectories = true)
{
bool bSubdirectory = false; // Flag, indicating whether
// subdirectories have been found
HANDLE hFile; // Handle to directory
std::string strFilePath; // Filepath
std::string strPattern; // Pattern
WIN32_FIND_DATA FileInformation; // File information
strPattern = refcstrRootDirectory + "\\*.*";
hFile = ::FindFirstFile(strPattern.c_str(), &FileInformation);
if(hFile != INVALID_HANDLE_VALUE)
{
do
{
if(FileInformation.cFileName[0] != '.')
{
strFilePath.erase();
strFilePath = refcstrRootDirectory + "\\" + FileInformation.cFileName;
if(FileInformation.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
{
if(bDeleteSubdirectories)
{
// Delete subdirectory
int iRC = DeleteDirectory(strFilePath, bDeleteSubdirectories);
if(iRC)
return iRC;
}
else
bSubdirectory = true;
}
else
{
// Set file attributes
if(::SetFileAttributes(strFilePath.c_str(),
FILE_ATTRIBUTE_NORMAL) == FALSE)
return ::GetLastError();
// Delete file
if(::DeleteFile(strFilePath.c_str()) == FALSE)
return ::GetLastError();
}
}
} while(::FindNextFile(hFile, &FileInformation) == TRUE);
// Close handle
::FindClose(hFile);
DWORD dwError = ::GetLastError();
if(dwError != ERROR_NO_MORE_FILES)
return dwError;
else
{
if(!bSubdirectory)
{
// Set directory attributes
if(::SetFileAttributes(refcstrRootDirectory.c_str(),
FILE_ATTRIBUTE_NORMAL) == FALSE)
return ::GetLastError();
// Delete directory
if(::RemoveDirectory(refcstrRootDirectory.c_str()) == FALSE)
return ::GetLastError();
}
}
}
return 0;
}
int main()
{
int iRC = 0;
std::string strDirectoryToDelete = "c:\\mydir";
// Delete 'c:\mydir' without deleting the subdirectories
iRC = DeleteDirectory(strDirectoryToDelete, false);
if(iRC)
{
std::cout << "Error " << iRC << std::endl;
return -1;
}
// Delete 'c:\mydir' and its subdirectories
iRC = DeleteDirectory(strDirectoryToDelete);
if(iRC)
{
std::cout << "Error " << iRC << std::endl;
return -1;
}
// Wait for keystroke
_getch();
return 0;
}
Use DeleteFile to delete file symbolic links.
Use RemoveDirectory to delete directory symbolic links and junctions.
In other words, you treat them just like any other file or directory except that you don't recurse into directories that have the FILE_ATTRIBUTE_REPARSE_POINT attribute.
The simplest way to achieve your goal, and the recommended way to do it, is to get the system to do the work.
If you need to support XP then you use SHFileOperation with the FO_DELETE flag.
Otherwise, for Vista and later, use IFileOperation.
These APIs handle all the details for you, and use the same code paths as does the shell. You can even show the standard shell progress UI if you desire.

List files in directory C++

I'm trying to use this example
to create a program which will list all filenames in a directory in a Windows::Forms::ListBox.
Since the user won't be doing any inputting I won't be needing the
void DisplayErrorBox(LPTSTR lpszFunction) function along with other error checking.
When I click the button that triggers the event this is what is shown in the list box.
o //&#o/
/ //
/ //
/ //
/ //
/ //
/ //
/ //
Also, only one row appear each time i click the button.
It's supposed to find all the files in the directory and list them not just find the next file each time I click the button.
I also want to use a relative strPath, not absolute...
So far this is what I've done with the code:
private:
void List_Files()
{
std::string strPath = "C:\\Users\\Andre\\Dropbox\\Programmering privat\\Diablo III DPS Calculator\\Debug\\SavedProfiles";
TCHAR* Path = (TCHAR*)strPath.c_str();
WIN32_FIND_DATA ffd;
LARGE_INTEGER filesize;
TCHAR szDir[MAX_PATH];
size_t length_of_arg;
HANDLE hFind = INVALID_HANDLE_VALUE;
// Prepare string for use with FindFile functions. First, copy the
// string to a buffer, then append '\*' to the directory name.
StringCchCopy(szDir, MAX_PATH, Path);
StringCchCat(szDir, MAX_PATH, TEXT("\\*"));
// List all the files in the directory with some info about them.
do
{
if (ffd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
{
//If it's a directory nothing should happen. Just continue with the next file.
}
else
{
//convert from wide char to narrow char array
char ch[260];
char DefChar = ' ';
WideCharToMultiByte(CP_ACP,0,(ffd.cFileName),-1, ch,260,&DefChar, NULL);
//A std:string using the char* constructor.
std::string str(ch);
String ^ sysStr = gcnew String(str.c_str());
MessageBox::Show("File Found", "NOTE");
ListBoxSavedFiles->Items->Add (sysStr);
}
}
while (FindNextFile(hFind, &ffd) != 0);
FindClose(hFind);
}
FindFirstFile() is never called, you need to call it before calling FindNextFile():
HANDLE hFind = FindFirstFile(TEXT("C:\\Users\\Andre\\Dropbox\\Programmering privat\\Diablo III DPS Calculator\\Debug\\SavedProfiles\\*"), &ffd);
if (INVALID_HANDLE_VALUE != hFind)
{
do
{
//...
} while(FindNextFile(hFind, &ffd) != 0);
FindClose(hFind);
}
else
{
// Report failure.
}
If you do not mind using Boost, you can use a directory_iterator:
using boost::filesystem;
path p("some_dir");
for (directory_iterator it(p); it != directory_iterator(); ++it) {
cout << it->path() << endl;
}
It works on Windows too and it definitely looks much simpler. Of course, you would need to adapt your current code a little bit, but I think in the long term it is well worth the effort.
The cast (TCHAR*)strPath.c_str(); is wrong. From your use of WideCharToMultiByte I know that (TCHAR*)strPath.c_str(); is casting a char const* to a wchar_t*. Not only does that lose a const, but the width is also wrong.
If u are using Visual Studio then change the configuration settings to Use Multibyte Character set. This will your TCHAR thing to compile without any cast.

Problems with Visual C++: Reading all files in a directory

I'm trying to read all files in a directory. I have the following code:
void scanDirectory(char* dir)
{
WIN32_FIND_DATA FindFileData;
HANDLE hFind = INVALID_HANDLE_VALUE;
char DirSpec[MAX_PATH]; // directory specification
strcpy(DirSpec, dir);
strcat(DirSpec, "\\*");
hFind = FindFirstFile(DirSpec, &FindFileData);
int i = 0;
do {
i++;
printf("%d \n", i);
if (FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
{
printf(" %s <DIR>\n", FindFileData.cFileName);
}
else
{
printf("File %s\n", FindFileData.cFileName);
}
} while(!FindNextFile(hFind, &FindFileData));
FindClose(hFind);
}
The problem is that when I execute the code it results in an infinite loop. Also the output characters are strange, like "File ".
I think you are not using chars and wide chars in a consequent way. You should either use functions with wide char and wchar_t type or vice versa. (But it was a compile error for me so it may depend on some kind of project settings as well.)
And your exit condition in the while loop is also wrong it should test for FindNextFile and not !FindNextFile. The infinite loop may be because of this condition as if it doesn't find any files it will run forever.
Also you should test for the return value of FindFirstFile and not go into the loop if it doesn't find any files.
You are calling !FindNextFile instead of FindNextFile, also you are not checking why
the FindNextFile fails, so you can't be sure if all the files were processed.
Use something like this.
WIN32_FIND_DATA stFindData;
HANDLE hFind = FindFirstFile(cSearchPattern, &stFindData);
if(hFind != INVALID_HANDLE_VALUE)
{
do
{
// Process File
}
while (FindNextFile(hFind, &stFindData) != 0);
DWORD dwError = GetLastError();
if (dwError != ERROR_NO_MORE_FILES)
{
// Not All Files processed, deal with Error
}
FindClose(hFind);
}
Can't you just use .Net like below:
System.IO.DirectoryInfo dir = new System.IO.DirectoryInfo(Path);
System.IO.FileInfo[] files = dir.GetFiles();
foreach (System.IO.FileInfo file in files)
{
// Do whatever you need with the file info...
string filename = file.Name;
string fullFilename = file.FullName;
}
This is a c# example but you can use for each in C++ the same. Hope this helps.

Why am I having problems recursively deleting directories?

I've written an application that uses the WIN32 api to create a temporarily directory hierarchy. Now, when wanting to delete the directories when shutting down the application I'm running into some problems.
So lets say I have a directory hierarchy: C:\temp\directory\subdirectory\
I'm using this recursive function:
bool Dir::deleteDirectory(std::string& directoryname, int flags)
{
if(directoryname.at(directoryname.size()-1) != '\\') directoryname += '\\';
if ((flags & CONTENTS) == CONTENTS)
{
WIN32_FIND_DATAA fdata;
HANDLE dhandle;
directoryname += "\\*";
dhandle = FindFirstFileA(directoryname.c_str(), &fdata);
// Loop through all the files in the main directory and delete files & make a list of directories
while(true)
{
if(FindNextFileA(dhandle, &fdata))
{
std::string filename = fdata.cFileName;
if(filename.compare("..") != 0)
{
std::string filelocation = directoryname.substr(0, directoryname.size()-2) + StringManip::reverseSlashes(filename);
// If we've encountered a directory then recall this function for that specific folder.
if(!isDirectory(filelocation)) DeleteFileA(filename.c_str());
else deleteDirectory(filelocation, DIRECTORY_AND_CONTENTS);
}
} else if(GetLastError() == ERROR_NO_MORE_FILES) break;
}
directoryname = directoryname.substr(0, directoryname.size()-2);
}
if ((flags & DIRECTORY) == DIRECTORY)
{
HANDLE DirectoryHandle;
DirectoryHandle = CreateFileA(directoryname.c_str(),
FILE_LIST_DIRECTORY,
FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
NULL,
OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OVERLAPPED,
NULL);
bool DeletionResult = (RemoveDirectoryA(directoryname.c_str()) != 0)?true:false;
CloseHandle(DirectoryHandle);
return DeletionResult;
}
return true;
}
This function iterates over the directory contents of the temp directory; and for each directory in the temp directory it keeps recalling itself until it's at the lowest directory; subdirectory in the example.
There are also 3 flags defined
enum DirectoryDeletion
{
CONTENTS = 0x1,
DIRECTORY = 0x2,
DIRECTORY_AND_CONTENTS = (0x1 | 0x2)
};
When using this function, it only removes the lowest subdirectory and I can't remove the ones higher in hierarchy because it says that the directory is not empty. When I go and look to the directory 'subdirectory' is only removed after the application ends. However, when I try to encapsulate this in a non recursive simple main application I have no problems at all with deleting the directories.
There's a Windows API, SHFileOperation, that will do a recursive folder delete for you.
LONG DeleteDirectoryAndAllSubfolders(LPCWSTR wzDirectory)
{
WCHAR szDir[MAX_PATH+1]; // +1 for the double null terminate
SHFILEOPSTRUCTW fos = {0};
StringCchCopy(szDir, MAX_PATH, wzDirectory);
int len = lstrlenW(szDir);
szDir[len+1] = 0; // double null terminate for SHFileOperation
// delete the folder and everything inside
fos.wFunc = FO_DELETE;
fos.pFrom = szDir;
fos.fFlags = FOF_NO_UI;
return SHFileOperation( &fos );
}
You're not closing dhandle from all those FindFirstFile calls, so each directory has a reference to it when you try to delete it.
And, why do you need to create DirectoryHandle? It's not needed, and will probably also block the directory deletion.
When your app closes, those handles are forced close, and (I guess) the last attempted delete then succeeds.
SHFileOperations works great on Windows 7. In fact in the IFileOperation documentation says
IFileOperation can only be applied in a single-threaded apartment (STA) situation. It cannot be used for a multithreaded apartment (MTA) situation. For MTA, you still must use SHFileOperation.
However my issue with SHFileOperations is it doesn't seem to support paths longer than 260 characters, and does not support \?\ prefix for long filenames.
This is a real pain....but a recursive function is still needed if you want ability to handle paths longer than 260 characters (Which NTFS supports - but not Windows Explorer, command prompt commands etc)
Well, I found several bugs in this code.. here is what I found
bool Dir::deleteDirectory(std::string& directoryname, int flags)
{
if(directoryname.at(directoryname.size()-1) != '\\') directoryname += '\\';
if ((flags & CONTENTS) == CONTENTS)
{
WIN32_FIND_DATAA fdata;
HANDLE dhandle;
//BUG 1: Adding a extra \ to the directory name..
directoryname += "*";
dhandle = FindFirstFileA(directoryname.c_str(), &fdata);
//BUG 2: Not checking for invalid file handle return from FindFirstFileA
if( dhandle != INVALID_HANDLE_VALUE )
{
// Loop through all the files in the main directory and delete files & make a list of directories
while(true)
{
if(FindNextFileA(dhandle, &fdata))
{
std::string filename = fdata.cFileName;
if(filename.compare("..") != 0)
{
//BUG 3: caused by BUG 1 - Removing too many characters from string.. removing 1 instead of 2
std::string filelocation = directoryname.substr(0, directoryname.size()-1) + filename;
// If we've encountered a directory then recall this function for that specific folder.
//BUG 4: not really a bug, but spurious function call - we know its a directory from FindData already, use it.
if( (fdata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) == 0)
DeleteFileA(filelocation.c_str());
else
deleteDirectory(filelocation, DIRECTORY_AND_CONTENTS);
}
} else if(GetLastError() == ERROR_NO_MORE_FILES) break;
}
directoryname = directoryname.substr(0, directoryname.size()-2);
//BUG 5: Not closing the FileFind with FindClose - OS keeps handles to directory open. MAIN BUG
FindClose( dhandle );
}
}
if ((flags & DIRECTORY) == DIRECTORY)
{
HANDLE DirectoryHandle;
DirectoryHandle = CreateFileA(directoryname.c_str(),
FILE_LIST_DIRECTORY,
FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
NULL,
OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OVERLAPPED,
NULL);
//BUG 6: Not checking CreateFileA for invalid handle return.
if( DirectoryHandle != INVALID_HANDLE_VALUE )
{
bool DeletionResult = (RemoveDirectoryA(directoryname.c_str()) != 0)?true:false;
CloseHandle(DirectoryHandle);
return DeletionResult;
}
else
{
return true;
}
}
return true;
}
Try calling FindClose to close handle returned by FindFileFileA.
I don't see a FindClose for your dhandle. An open handle means that the directory is still in use.
MSDN says: "When the search handle is no longer needed, close it by using the FindClose function, not CloseHandle."
(CloseHandle appears to be correct for your DirectoryHandle further down, but not for the dhandle used in the Find loop.)
The main issue has already been answered, but here's something I noticed. Your main while loop seems a bit fragile to me...
while(true)
{
if(FindNextFileA(dhandle, &fdata))
{
//...
} else if(GetLastError() == ERROR_NO_MORE_FILES) break;
}
This ends if FindNextFile ends because there are no more files in the directory. But what if it ever ends for some other reason? If something abnormal happens, it seems you could end up with an infinite loop.
I'd think if FindNextFile fails for any reason, then you'll want to stop the loop and start returning through the recursive calls. So I'd suggest simply removing the GetLastError test and just making it "else break;"
Actually, after a moment's thought I would probably just reduce it to:
while(FindNextFileA(dhandle, &fdata))
{
//...
}