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/*
This file is part of the KDE libraries
Copyright (c) 1999 Waldo Bastian <bastian@kde.org>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License version 2 as published by the Free Software Foundation.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#ifndef _KTEMPFILE_H_
#define _KTEMPFILE_H_
#include <qstring.h>
#include <stdio.h>
#include <errno.h>
#include "kdelibs_export.h"
class QFile;
class QTextStream;
class QDataStream;
class KSaveFile;
class KTempFilePrivate;
/**
* The KTempFile class creates and opens a unique file for temporary use.
*
* This is especially useful if you need to create a file in a world
* writable directory like /tmp without being vulnerable to so called
* symlink attacks.
*
* KDE applications, however, shouldn't create files in /tmp in the first
* place but use the "tmp" resource instead. The standard KTempFile
* constructor will do that by default.
*
* To create a temporary file that starts with a certain name
* in the "tmp" resource, one should use:
* KTempFile(locateLocal("tmp", prefix), extension);
*
* KTempFile does not create any missing directories, but locateLocal() does.
*
* See also KStandardDirs
*
* @author Waldo Bastian <bastian@kde.org>
*/
class KDECORE_EXPORT KTempFile
{
friend class KSaveFile;
public:
/**
* Creates a temporary file with the name:
* \<filePrefix>\<six letters>\<fileExtension>
*
* The default @p filePrefix is "$KDEHOME/tmp-$HOST/appname/"
* The default @p fileExtension is ".tmp"
* @param filePrefix the prefix of the file name, or QString::null
* for the default value
* @param fileExtension the extension of the prefix, or QString::null for the
* default value
* @param mode the file permissions
**/
KTempFile(QString filePrefix=QString::null,
QString fileExtension=QString::null,
int mode = 0600 );
/**
* The destructor closes the file.
* If autoDelete is enabled the file gets unlinked as well.
**/
~KTempFile();
/**
* Turn automatic deletion on or off.
* Automatic deletion is off by default.
* @param autoDelete true to turn automatic deletion on
**/
void setAutoDelete(bool autoDelete) { bAutoDelete = autoDelete; }
/**
* Returns the status of the file based on errno. (see errno.h)
* 0 means OK.
*
* You should check the status after object creation to check
* whether a file could be created in the first place.
*
* You may check the status after closing the file to verify that
* the file has indeed been written correctly.
* @return the errno status, 0 means ok
**/
int status() const;
/**
* Returns the full path and name of the file.
*
* Note that in most circumstances the file needs to be closed
* before you use it by name.
*
* In particular, if another process or software part needs to write data
* to the file based on the filename, the file should be closed before doing
* so. Otherwise the act of closing the file later on may cause the file to
* get truncated to a zero-size, resulting in an unexpected loss of the data.
*
* In some cases there is only interest in the filename itself but where the
* actual presence of a file with such name is a problem. In that case the
* file should first be both closed and unlinked. Such usage is not recommended
* since it may lead to the kind of symlink vulnerabilities that the KTempFile
* design attempts to prevent.
*
* @return The name of the file, or QString::null if opening the
* file has failed or the file has been unlinked already.
**/
QString name() const;
/**
* An integer file descriptor open for writing to the file
* @return The file descriptor, or a negative number if opening
* the file failed
**/
int handle() const;
/**
* Returns the FILE* of the temporary file.
* @return FILE* stream open for writing to the file, or 0
* if opening the file failed
**/
FILE *fstream();
/**
* Returns the QTextStream for writing.
* @return QTextStream open for writing to the file, or 0
* if opening the file failed
**/
QTextStream *textStream();
/**
* Returns a QDataStream for writing.
* @return QDataStream open for writing to the file, or 0
* if opening the file failed
**/
QDataStream *dataStream();
/**
* Returns a QFile.
* @return A QFile open for writing to the file, or 0 if
* opening the file failed.
**/
QFile *file();
/**
* Unlinks the file from the directory. The file is
* deleted once the last reader/writer closes it.
**/
void unlink();
/**
* Flushes file to disk (fsync).
*
* If you want to be as sure as possible that the file data has
* actually been physically stored on disk you need to call sync().
*
* See status() for details about errors.
* @return true if successful, or false if an error has occurred.
* @since 3.3
**/
bool sync();
/**
* Closes the file.
*
* See status() for details about errors.
* @return true if successful, or false if an error has occurred.
**/
bool close();
protected:
/**
* Constructor used by KSaveFile
**/
KTempFile(bool);
/**
* @internal
* Create function used internally by KTempFile and KSaveFile
**/
bool create(const QString &filePrefix,
const QString &fileExtension, int mode);
void setError(int error) { mError = error; }
private:
int mError;
QString mTmpName;
int mFd;
FILE *mStream;
QFile *mFile;
QTextStream *mTextStream;
QDataStream *mDataStream;
bool bOpen;
bool bAutoDelete;
KTempFilePrivate *d;
};
#endif
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