Is there a Qt function to move files to Recycle Bin instead of truly deleting them, for OSes that support it, or do I need to use OS-specific code?
Since Qt 5.15.0 Alpha, this method has been added, which should be what you were looking for.
bool QFile::moveToTrash()
The corresponding code changes can be found here.
(This issue is old and the corresponding Bugreport at https://bugreports.qt.io/browse/QTBUG-47703 has already been posted, but I currently lack the reputation to comment, and found this to be a useful information.)
Qt doesnt provide a MoveToTrash. Here's a part of my code
for Windows
#ifdef Q_OS_WIN32
#include "windows.h"
void MoveToTrashImpl( QString file ){
QFileInfo fileinfo( file );
if( !fileinfo.exists() )
throw OdtCore::Exception( "File doesnt exists, cant move to trash" );
WCHAR from[ MAX_PATH ];
memset( from, 0, sizeof( from ));
int l = fileinfo.absoluteFilePath().toWCharArray( from );
Q_ASSERT( 0 <= l && l < MAX_PATH );
from[ l ] = '\0';
SHFILEOPSTRUCT fileop;
memset( &fileop, 0, sizeof( fileop ) );
fileop.wFunc = FO_DELETE;
fileop.pFrom = from;
fileop.fFlags = FOF_ALLOWUNDO | FOF_NOCONFIRMATION | FOF_NOERRORUI | FOF_SILENT;
int rv = SHFileOperation( &fileop );
if( 0 != rv ){
qDebug() << rv << QString::number( rv ).toInt( 0, 8 );
throw OdtCore::Exception( "move to trash failed" );
}
}
#endif
and for Linux
#ifdef Q_OS_LINUX
bool TrashInitialized = false;
QString TrashPath;
QString TrashPathInfo;
QString TrashPathFiles;
void MoveToTrashImpl( QString file ){
#ifdef QT_GUI_LIB
if( !TrashInitialized ){
QStringList paths;
const char* xdg_data_home = getenv( "XDG_DATA_HOME" );
if( xdg_data_home ){
qDebug() << "XDG_DATA_HOME not yet tested";
QString xdgTrash( xdg_data_home );
paths.append( xdgTrash + "/Trash" );
}
QString home = QStandardPaths::writableLocation( QStandardPaths::HomeLocation );
paths.append( home + "/.local/share/Trash" );
paths.append( home + "/.trash" );
foreach( QString path, paths ){
if( TrashPath.isEmpty() ){
QDir dir( path );
if( dir.exists() ){
TrashPath = path;
}
}
}
if( TrashPath.isEmpty() )
throw Exception( "Cant detect trash folder" );
TrashPathInfo = TrashPath + "/info";
TrashPathFiles = TrashPath + "/files";
if( !QDir( TrashPathInfo ).exists() || !QDir( TrashPathFiles ).exists() )
throw Exception( "Trash doesnt looks like FreeDesktop.org Trash specification" );
TrashInitialized = true;
}
QFileInfo original( file );
if( !original.exists() )
throw Exception( "File doesnt exists, cant move to trash" );
QString info;
info += "[Trash Info]\nPath=";
info += original.absoluteFilePath();
info += "\nDeletionDate=";
info += QDateTime::currentDateTime().toString("yyyy-MM-ddThh:mm:ss.zzzZ");
info += "\n";
QString trashname = original.fileName();
QString infopath = TrashPathInfo + "/" + trashname + ".trashinfo";
QString filepath = TrashPathFiles + "/" + trashname;
int nr = 1;
while( QFileInfo( infopath ).exists() || QFileInfo( filepath ).exists() ){
nr++;
trashname = original.baseName() + "." + QString::number( nr );
if( !original.completeSuffix().isEmpty() ){
trashname += QString( "." ) + original.completeSuffix();
}
infopath = TrashPathInfo + "/" + trashname + ".trashinfo";
filepath = TrashPathFiles + "/" + trashname;
}
QDir dir;
if( !dir.rename( original.absoluteFilePath(), filepath ) ){
throw Exception( "move to trash failed" );
}
File infofile;
infofile.createUtf8( infopath, info );
#else
Q_UNUSED( file );
throw Exception( "Trash in server-mode not supported" );
#endif
}
#endif
There is no API yet.
https://bugreports.qt.io/browse/QTBUG-181
The issue is closed and the fix version is: Some future release
Edit: A new issue has been opened at https://bugreports.qt.io/browse/QTBUG-47703.
Edit Apparently it is now done in 5.15.0 Alpha bool QFile::moveToTrash()
I think that there is no cross-platform way. Simple moving files to "trash" location will not give effect, because user may switch off this possibility.
Maybe, this url will help: http://www.hardcoded.net/articles/send-files-to-trash-on-all-platforms.htm
I'm relatively certain that there is no Qt API that wraps this for all supported platforms. That means, unfortunately, that you will have to write platform-specific code.
I don't know anything about where/how Linux distributions store deleted files, and I imagine that it probably varies depending on which file manager you're using. I believe that moving files to a ~/.Trash folder is the standard way of doing it, but I'm not sure if this is reliable. For example, in the case of files stored on external volumes.
Things are a bit easier on Mac OS X, where there is a supported API to do this: FSMoveObjectToTrashSync, provided by Core Services. At least, that's how I remember you're supposed to do it. The documentation claims that this method is now deprecated in OS X 10.8. I have no idea what the recommended alternative is.
As a Windows programmer, I think that platform is much easier. :-) The basic solution is to call the SHFileOperation function:
#include <Windows.h> // general Windows header file
#include <ShellAPI.h> // for shell functions, like SHFileOperation
#include <string> // (or use QString)
void RecycleFileOnWindows()
{
std::wstring path = L"C:\\Users\\Administrator\\Documents\\deleteme.txt";
path.append(1, L'\0'); // path string must be double nul-terminated
SHFILEOPSTRUCT shfos = {};
shfos.hwnd = nullptr; // handle to window that will own generated windows, if applicable
shfos.wFunc = FO_DELETE;
shfos.pFrom = path.c_str();
shfos.pTo = nullptr; // not used for deletion operations
shfos.fFlags = FOF_ALLOWUNDO; // use the recycle bin
const int retVal = SHFileOperation(&shfos);
if (retVal != 0)
{
// The operation failed...
if (shfos.fAnyOperationsAborted)
{
// ...but that's because the user canceled.
MessageBox(nullptr, L"Operation was canceled", nullptr, MB_OK | MB_ICONINFORMATION);
}
else
{
// ...for one of the other reasons given in the documentation.
MessageBox(nullptr, L"Operation failed", nullptr, MB_OK | MB_ICONERROR);
}
}
}
There are also flags that you can set to customize confirmation, error reporting, and other behavior. The linked documentation contains all the details you need to build upon this basic example.
On Windows Vista and later, the SHFileOperation function has been superseded by the methods provided by the IFileOperation interface. If you're targeting only these later versions of Windows, you should prefer to use this interface. Otherwise, SHFileOperation will continue to work fine.
if(QSysInfo::kernelType()=="linux")
{
QDateTime currentTime(QDateTime::currentDateTime()); // save System time
QString trashFilePath=QDir::homePath()+"/.local/share/Trash/files/"; // trash file path contain delete files
QString trashInfoPath=QDir::homePath()+"/.local/share/Trash/info/"; // trash info path contain delete files information
// create file format for trash info file----- START
QFile infoFile(trashInfoPath+FileName.completeBaseName()+"."+FileName.completeSuffix()+".trashinfo"); //filename+extension+.trashinfo // create file information file in /.local/share/Trash/info/ folder
infoFile.open(QIODevice::ReadWrite);
QTextStream stream(&infoFile); // for write data on open file
stream<<"[Trash Info]"<<endl;
stream<<"Path="+QString(QUrl::toPercentEncoding(FileName.absoluteFilePath(),"~_-./"))<<endl; // convert path string in percentage decoding scheme string
stream<<"DeletionDate="+currentTime.toString("yyyy-MM-dd")+"T"+currentTime.toString("hh:mm:ss")<<endl; // get date and time format YYYY-MM-DDThh:mm:ss
infoFile.close();
// create info file format of trash file----- END
QDir file;
file.rename(FileName.absoluteFilePath(),trashFilePath+FileName.completeBaseName()+"."+FileName.completeSuffix()); // rename(file old path, file trash path)
}
Trash files in linux exist /home/user_name/.local/share/Trash/files/ directory but it also require info file for each trash file which exist in /home/user_name/.local/share/Trash/info/ directory. when we want to move file into trash, actually move file into /home/user_name/.local/share/Trash/files/ directory and create info file in /home/user_name/.local/share/Trash/info/ directory. inside .trashinfo format use percentage decoding scheme for set file path where file existed, info file also contain time and date of deletion.
Related
First off, I do mostly C#, .Net development so go easy on me if this is a stupid question.
I am implementing an Ericcson open source project to convert an image to another format. The problem is that on conversion an output to a console happens as follows...
1 file(s) copied.
I need to suppress this dialog that pops up. I just want to execute the system command with no output. I think I have isolated the area of the code causing this.
void writeOutputFile(char *dstfile, uint8* img, uint8* alphaimg, int width, int height)
{
char str[300];
if(format!=ETC2PACKAGE_R_NO_MIPMAPS&&format!=ETC2PACKAGE_RG_NO_MIPMAPS)
{
fWritePPM("tmp.ppm",width,height,img,8,false);
//PRINTF("Saved file tmp.ppm \n\n");
}
else if(format==ETC2PACKAGE_RG_NO_MIPMAPS)
{
fWritePPM("tmp.ppm",width,height,img,16,false);
}
if(format==ETC2PACKAGE_RGBA_NO_MIPMAPS||format==ETC2PACKAGE_RGBA1_NO_MIPMAPS||format==ETC2PACKAGE_sRGBA_NO_MIPMAPS||format==ETC2PACKAGE_sRGBA1_NO_MIPMAPS)
fWritePGM("alphaout.pgm",width,height,alphaimg,false,8);
if(format==ETC2PACKAGE_R_NO_MIPMAPS)
fWritePGM("alphaout.pgm",width,height,alphaimg,false,16);
// Delete destination file if it exists
if(fileExist(dstfile))
{
sprintf(str, "del %s\n",dstfile);
system(str);
}
int q = find_pos_of_extension(dstfile);
if(!strcmp(&dstfile[q],".ppm")&&format!=ETC2PACKAGE_R_NO_MIPMAPS)
{
// Already a .ppm file. Just rename.
sprintf(str,"move tmp.ppm %s\n",dstfile);
//PRINTF("Renaming destination file to %s\n",dstfile);
}
else
{
// Converting from .ppm to other file format
//
// Use your favorite command line image converter program,
// for instance Image Magick. Just make sure the syntax can
// be written as below:
//
// C:\imconv source.ppm dest.jpg
//
if(format==ETC2PACKAGE_RGBA_NO_MIPMAPS||format==ETC2PACKAGE_RGBA1_NO_MIPMAPS||format==ETC2PACKAGE_sRGBA_NO_MIPMAPS||format==ETC2PACKAGE_sRGBA1_NO_MIPMAPS)
{
// Somewhere after version 6.7.1-2 of ImageMagick the following command gives the wrong result due to a bug.
// sprintf(str,"composite -compose CopyOpacity alphaout.pgm tmp.ppm %s\n",dstfile);
// Instead we read the file and write a tga.
//PRINTF("Converting destination file from .ppm/.pgm to %s with alpha\n",dstfile);
int rw, rh;
unsigned char *pixelsRGB;
unsigned char *pixelsA;
fReadPPM("tmp.ppm", rw, rh, pixelsRGB, 8);
fReadPGM("alphaout.pgm", rw, rh, pixelsA, 8);
fWriteTGAfromRGBandA(dstfile, rw, rh, pixelsRGB, pixelsA, true);
free(pixelsRGB);
free(pixelsA);
sprintf(str,""); // Nothing to execute.
}
else if(format==ETC2PACKAGE_R_NO_MIPMAPS)
{
sprintf(str,"imconv alphaout.pgm %s\n",dstfile);
//PRINTF("Converting destination file from .pgm to %s\n",dstfile);
}
else
{
sprintf(str,"imconv tmp.ppm %s\n",dstfile);
//PRINTF("Converting destination file from .ppm to %s\n",dstfile);
}
}
// Execute system call
system(str);
free(img);
if(alphaimg!=NULL)
free(alphaimg);
}
I am lost at this point about how to suppress the console that pops up. As we iterate through images via a reference to the dll, many many console windows flash on the screen. Need to stop this from happening.
Help is greatly appreciated.
Try doing:
strcat( str, " > nul" ) // for Windows or
//strcat( str, " > /dev/null" ) // for Unix
system( str )
If it doesn't help then this may help:
#include <string>
#include <ShellAPI.h>
int system_no_output( std::string command )
{
command.insert( 0, "/C " );
SHELLEXECUTEINFOA ShExecInfo = {0};
ShExecInfo.cbSize = sizeof(SHELLEXECUTEINFO);
ShExecInfo.fMask = SEE_MASK_NOCLOSEPROCESS;
ShExecInfo.hwnd = NULL;
ShExecInfo.lpVerb = NULL;
ShExecInfo.lpFile = "cmd.exe";
ShExecInfo.lpParameters = command.c_str();
ShExecInfo.lpDirectory = NULL;
ShExecInfo.nShow = SW_HIDE;
ShExecInfo.hInstApp = NULL;
if( ShellExecuteExA( &ShExecInfo ) == FALSE )
return -1;
WaitForSingleObject( ShExecInfo.hProcess, INFINITE );
DWORD rv;
GetExitCodeProcess( ShExecInfo.hProcess, &rv );
CloseHandle( ShExecInfo.hProcess );
return rv;
}
and replace all your system() calls to system_no_output() ones.
To fully suppress the output, redirect both stdout and stderr:
system("command >nul 2>nul");
Take a look here if you're using C#. The class used in C# is ProcessStartInfo.
In the example in the link, look at the OpenWithStartInfo member function which will minimize the console.
As far as doing this in C++, take a look at the spawn family of functions here.
I was wondering if there is a way to change a file extension via any c++ facilities.
Example: .txt to .xyz
The extension is just part of the filename, and to change it you simply have to rename the file. For that you have two choices, the POSIX compliant rename function in the CRT, or the WIN32 function MoveFile (and its variants).
the Rename function is actually performed directly on a file
int main ()
{
int result =1;
char oldname[] ="oldname.txt";
char newname[] ="newname.docx";
FILE* fp = fopen(oldname , "r+" );
bool exists = (fp != NULL);
if (exists)
{
fclose(fp);
result= rename( oldname , newname );
}
if ( result == 0 )
puts ( "File successfully renamed" );
else
perror( "Error renaming file" );
return 0;
}
is there any way to enable user to select file manually using GUI in my cpp console application with OpenCV? I've made some research but found no solution for such trivial task so far...
Thanks in advance,
JP
For this, you have to add any available gui library and handle the gui part with that keeping the image processing part to opnecv. ( For example, you can try Qt )
If you want to a simple file open dialog in Ubuntu, you can do this:
FILE *in;
if (!(in = popen(
"zenity --title=\"Select an image\" --file-selection",
"r"))) {
return 1;
}
char buff[512];
string selectFile = "";
while (fgets(buff, sizeof(buff), in) != NULL) {
selectFile += buff;
}
pclose(in);
//remove the "\n"
selectFile.erase(std::remove(selectFile.begin(), selectFile.end(), '\n'),
selectFile.end());
// path + filename + format
Mat image = imread(selectFile);
As title says I'm getting this error while trying to open file for binary writing(mode doesnt seem matter).
My app uses libev to handle sockets(non blocking/epoll backend) and while parsing client packets i want at some point where i receive fileupload message to start writing down to disk data i get from server.
I couldn't google anything about EAGAIN(Resource temporarily unavailable) message and file opening..
These are methods I've tried:
fopen( ... ) returns EAGAIN
using ofstream/fstream's open(...) by creating them on heap(new) returns EAGAIN
using ofstream/fstream's open(...) staticly as class member (ofstream m_ofFile;) works, but strangly compiler generates code which calls ofstream destructor and closes file before exiting class method im calling .open from. Now that contradicts with my C++ knowledge where for class members which are class types, destructors are called right before class owner's..
edit:
#Joachim
You're right, I'm not acually getting this error..(method #1. gonna test method #2 again soon). File opens regulary and i get regular FILE*. That happens in Init(...) function of my class, but then when I call OnFileChunk later on m_hFile is 0 and therefor i cant write to it. Here is complete class code:
class CFileTransferCS
{
wstring m_wszfile;
wstring m_wszLocalUserFolderPath;
int m_nChunkIndex;
int m_nWrittenBytes;
int m_nFileSize;
FILE* m_hFile;
CFileTransferCS( const CFileTransferCS& c ){}
CFileTransferCS& operator=( const CFileTransferCS& c ){}
public:
CFileTransferCS( );
CFileTransferCS( wstring file, uint32_t size );
void OnFileChunk( char* FileChunk, int size );
void Init( wstring file, uint32_t size );
void SetLocalUserLocalPath( wstring path );
};
CFileTransferCS::CFileTransferCS( )
{
m_hFile = NULL;
m_wszLocalUserFolderPath = L"";
m_nChunkIndex = 0;
m_nWrittenBytes = 0;
}
CFileTransferCS::CFileTransferCS( wstring file, uint32_t size )
{
m_nChunkIndex = 0;
m_nWrittenBytes = 0;
m_wszfile = file;
m_nFileSize = size;
wstring wszFullFilePath = m_wszLocalUserFolderPath + m_wszfile.substr( m_wszfile.find_last_of(L"\\") + 1 );
// string fp = string( file.begin(),file.end() );
string fp ="test.bin"; //for testing purposes
this->m_hFile = fopen(fp.c_str(),"wb");
printf("fp: %s hFile %d\n",fp.c_str(),this->m_hFile); //everything's fine here...
if(!this->m_hFile)
{
perror ("cant open file ");
}
}
void CFileTransferCS::SetLocalUserLocalPath( wstring path )
{
m_wszLocalUserFolderPath = path;
}
void CFileTransferCS::Init( wstring file, uint32_t size )
{
// If previous transfer session got interrupted for whatever reason
// close and delete old file and open new one
if( this->m_hFile )
{
printf("init CS transfer: deleting old file///\n");
fclose( this->m_hFile );
string fp = string( file.begin(),file.end() );
if( remove( fp.c_str() ))
{
//cant delete file...
}
}
CFileTransferCS( file, size );
}
void CFileTransferCS::OnFileChunk( char* FileChunk, int size )
{
for (;;)
{
printf("ofc: hFile %d\n",this->m_hFile); //m_hFile is 0 here...
if( !this->m_hFile )
{
// m_pofFile->open("kurac.txt",fstream::out);
printf("file not opened!\n");
break;
}
int nBytesWritten = fwrite( FileChunk, 1, size, this->m_hFile );
if( !nBytesWritten )
{
perror("file write!!\n");
break;
}
m_nWrittenBytes+=size;
if( m_nWrittenBytes == m_nFileSize )
{
fclose( m_hFile );
printf("file uplaod transfer finished!!!\n");
}
break;
}
printf("CFileTransferCS::OnFileChunk size: %d m_nWrittenBytes: %d m_nFileSize: %d\n",size,m_nWrittenBytes,m_nFileSize);
}
final edit:
I got it.. Calling explicitly CFileTransferCS( wstring file, uint32_t size ) constructor made problems.. Calling constructor like this explicitly caused that this pointer in it wasnt original one(that Init function was using) so when i was opening file from it and saving handle to m_hFile, i was doing it in some other object(now im not sure if CFileTransferCS(..) call allocated memory for CFileTransferCS object or it corrupted some other part of memory randomly.. will check it out with IDA later on )
Thanks to everyone and my apologies.
Regards, Mike –
#MikeJacksons answer:
Calling explicitly CFileTransferCS( wstring file, uint32_t size ) constructor made problems. Calling constructor like this explicitly caused that this pointer in it wasnt original one(that Init function was using) so when i was opening file from it and saving handle to m_hFile, i was doing it in some other object(now im not sure if CFileTransferCS(..) call allocated memory for CFileTransferCS object or it corrupted some other part of memory randomly.. will check it out with IDA later on ) Thanks everyone and my apologies.
Removed: CFileTransferCS( file, size );
(No need to appologize Mike, looks like you did a great job hunting down the bug).
I made an application and a dll, which are working this way:
I have to register the dll. After registering the dll if i right click on an .exe file, the pop-up menu appears, and i have inserted into this menu one line ("Start MyApp"), and if i click there, it should start MyApp. MyApp has one parameter which is the full path of the selected .exe file. After starting MyApp with this path it should create a process with CreateProcessWithLogonW(). This application reads the username, password and the domain from an .ini file. My problem is, that after MyApp starts, it fails always, because it can't find the ini file. Errorcode is: 1 (Incorrect function).
If i start MyApp manually, than it works fine.
Does anyone has any idea why is this, and how could i fix this problem?
Thanks in advance!
kampi
Update1:
Here is the code which reads from the ini file.
int main ( int argc, char *argv[] )
{
int i, slash = 0, j;
char application[size];
wchar_t wuser[65], wdomain[33], wpass[129];
memset( user, 0, sizeof ( user ) );
memset( password, 0, sizeof ( password ) );
memset( domain, 0, sizeof ( domain ) );
file_exists( "RunAs.ini" );
readfile( "RunAs.ini" );
....
....
....
}
void file_exists( const char * filename )
{
if (FILE * file = fopen(filename, "r"))
{
fclose(file);
}
else
{
printf("\nCan't find %s!\n",filename);
getch();
exit(1);
}
}//file_exists
void readfile( char * filename )
{
FILE *inifile;
char tmp[256], buf[256], what[128];
int i, j;
inifile = fopen( "RunAs.ini", "r" );
while ( fgets(tmp, sizeof tmp, inifile) != NULL )
{
if ( tmp[ strlen(tmp) - 1 ] == '\n' )
{
tmp[ strlen(tmp) - 1 ] = '\0';
}//if
memset ( buf, 0, sizeof( buf ) );
for ( i = 0; tmp[i]!= '='; i++ )
{
buf[i] = tmp[i];
}
buf[i] = '\0';
i++;
// memset ( what, 0, sizeof( what ) );
SecureZeroMemory( what, sizeof(what) * 128 );
for ( j = 0; i != strlen(tmp); i++ )
{
what[j] = tmp[i];
j++;
}
what[j] = '\0';
upcase( buf );
removespace( what );
if ( strcmp( buf, "USERNAME" ) == 0 )
{
strcpy( user, what );
}
if ( strcmp( buf, "PASSWORD" ) == 0 )
{
strcpy( password, what );
}
if ( strcmp( buf, "DOMAIN" ) == 0 )
{
strcpy( domain, what );
}
}//while
fclose (inifile);
}//readfile
As others have said, your problem is here:
file_exists( "RunAs.ini" );
readfile( "RunAs.ini" );
Neither of the function calls provides a path. You're expecting the current working directory to be the folder where your application is located, but it doesn't have to be (in fact, you should never assume that it is). The context menu isn't setting the working directory first.
Your safest bet is to retrieve the path to your folder using the path provided in argv[] (the 0th element is the fully qualified path and name of the application itself, and you can extract the path from that). You'll then have exact knowledge of where the file is located, and can append the name of the ini file to that path.
I suspect you're looking for the ini file in the wrong folder. I would try changing the ini file name in the application to the fully qualified name of the ini file. (i.e from "foo.ini" to "c:\\temp\\foo.ini")
(Please note that I've doubled the backslashes because without this, the single backslash may change the meaning of the next character or the backslash may be ignored.)
Are you providing an absolute path or a relative path? Your CWD may be different on startup.
When starting your application directly, the current path is the path that your application is installed to.
However, when starting it from that context menu, the current path is something else.
There are two ways to resolve this. First, don't use an ini file. Instead, store your information to the registry. That way you don't care where the program is started from.
Alternatively, your app will have to locate the directory where it was actually installed, then load the ini file from there.
Obviously the first choice is the easiest path.
Have you checked whether file path for the ini is valid ?