QFile::remove doesn't work

[mentalmushroom]

Hello. I noticed QFile::remove has problems with deleting files sometimes, namely I can't delete the video file. I think it is somehow related to sharing violation, BUT with WinAPI function DeleteFile it is deleted without any problems, so I suppose there is some bug in QFile. I have this issue always with that file, so it is easy to reproduce.

Sample:

// returns false
QFile::remove("C:/Users/shroom/Documents/TestIt/downloads/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3-XviK/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3.CD1-XviK.avi");
 
// returns 1 and deletes fine
DeleteFileA("C:/Users/shroom/Documents/TestIt/downloads/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3-XviK/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3.CD1-XviK.avi");

// returns false
QFile::remove("C:/Users/shroom/Documents/TestIt/downloads/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3-XviK/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3.CD1-XviK.avi");

// returns 1 and deletes fine
DeleteFileA("C:/Users/shroom/Documents/TestIt/downloads/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3-XviK/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3.CD1-XviK.avi");

To copy to clipboard, switch view to plain text mode 

I am using Qt 4.7.2 and my operating system is Windows 7 x64

[high_flyer]

What does permissions return?

QFile::Permissions permissions =QFile::permissions("C:/Users/shroom/Documents/TestIt/downloads/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3-XviK/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3.CD1-XviK.avi");

QFile::Permissions permissions =QFile::permissions("C:/Users/shroom/Documents/TestIt/downloads/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3-XviK/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3.CD1-XviK.avi");

To copy to clipboard, switch view to plain text mode 

[mcosta]

Print the QIODevice::errorString() to know why QFile::remove fails

[mentalmushroom]

What does permissions return?

Return zero.

Print the QIODevice::errorString() to know why QFile::remove fails

It prints "No such file or directory", but the file obviously exists.

[high_flyer]

Return zero.

Which OS are you on?
You probably don't have permission checking on.
Read here on how to do it:
http://doc.qt.nokia.com/latest/qfile...ermission-enum

[mentalmushroom]

Qt 4.7.2 + windows 7 x64. I didn't compile qt from source (downloaded binaries instead).

[high_flyer]

This is not a change in the Qt source, but in your own code.
This will turn the permission checking on.
Read the doc carefully.

t is possible to force permission checking on NTFS by including the following code in your source:

[mentalmushroom]

Ok, I changed my code to the following one. Still the same problem.

#include <windows.h>
#include <QtCore>
 
extern Q_CORE_EXPORT int qt_ntfs_permission_lookup;
 
int main(int argc, char *argv[])
{ 
 qt_ntfs_permission_lookup++;
 // also tried qt_ntfs_permission_lookup = 1
 
 // returns false
 QFile::remove("C:/Users/shroom/Documents/TestIt/downloads/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3-XviK/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3.CD1-XviK.avi");
 
 // returns 1 and deletes fine
 DeleteFileA("C:/Users/shroom/Documents/TestIt/downloads/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3-XviK/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3.CD1-XviK.avi");
}

#include <windows.h>
#include <QtCore>

extern Q_CORE_EXPORT int qt_ntfs_permission_lookup;

int main(int argc, char *argv[])
{ 
 qt_ntfs_permission_lookup++;
 // also tried qt_ntfs_permission_lookup = 1

 // returns false
 QFile::remove("C:/Users/shroom/Documents/TestIt/downloads/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3-XviK/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3.CD1-XviK.avi");
 
 // returns 1 and deletes fine
 DeleteFileA("C:/Users/shroom/Documents/TestIt/downloads/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3-XviK/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3.CD1-XviK.avi");
}

To copy to clipboard, switch view to plain text mode 

[high_flyer]

Its nice that you turned NTFS permission checking on, but if you don't use it, there is little point in havening it on, right?
Please answer post #2 again, now that permissions is turned on.

Another thing that might be wrong, are the slashes.
Try doubling the slashes and/or reversing them.

[mentalmushroom]

Ok, perhaps, I don't understand something. How should I "use" those permissions. I try to call f.setPermissions(QFile::WriteOther). For winapi function I don't need any permissions. For other files in the same folder I don't need permissions either, but this seems to be a strange avi file that, I guess, is used by something for preview or another background task. Answer to post #2 is the same: "No such file or directory".

#include <windows.h>
#include <QtCore>
 
extern Q_CORE_EXPORT int qt_ntfs_permission_lookup;
 
int main(int argc, char *argv[])
{ 
 qt_ntfs_permission_lookup++;
 // also tried qt_ntfs_permission_lookup = 1
 
QFile f("C:\\Users\\shroom\\Documents\\TestIt\\downloads\\The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3-XviK\\The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3.CD1-XviK.avi"); 
 
f.setPermissions(QFile::WriteOther);
 
 // returns false
 f.remove();
 
 // returns 1 and deletes fine
 DeleteFileA("C:/Users/shroom/Documents/TestIt/downloads/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3-XviK/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3.CD1-XviK.avi");
 
 return 0;
}

#include <windows.h>
#include <QtCore>
 
extern Q_CORE_EXPORT int qt_ntfs_permission_lookup;
 
int main(int argc, char *argv[])
{ 
 qt_ntfs_permission_lookup++;
 // also tried qt_ntfs_permission_lookup = 1
 
QFile f("C:\\Users\\shroom\\Documents\\TestIt\\downloads\\The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3-XviK\\The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3.CD1-XviK.avi"); 

f.setPermissions(QFile::WriteOther);

 // returns false
 f.remove();
 
 // returns 1 and deletes fine
 DeleteFileA("C:/Users/shroom/Documents/TestIt/downloads/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3-XviK/The.Matrix.1999.iNTERNAL.DVDRip.XviD.AC3.CD1-XviK.avi");

 return 0;
}

To copy to clipboard, switch view to plain text mode 

[VikMorroHun]

I had the same problem. I was "this" close to learn how to use Windows API and replace the QFile::remove() function in my code since it doesn't work, when I realized I tried to remove a file with Read Only attribute... Aaahhh...