KTempFile Class Reference

The KTempFile class creates and opens a unique file for temporary use. More...

#include <ktempfile.h>

List of all members.

Public Member Functions
bool	close ()
QDataStream *	dataStream ()
QFile *	file ()
FILE *	fstream ()
int	handle () const
	KTempFile (QString filePrefix=QString::null, QString fileExtension=QString::null, int mode=0600)
QString	name () const
void	setAutoDelete (bool autoDelete)
int	status () const
bool	sync ()
QTextStream *	textStream ()
void	unlink ()
	~KTempFile ()
Protected Member Functions
bool	create (const QString &filePrefix, const QString &fileExtension, int mode)
	KTempFile (bool)
void	setError (int error)

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Detailed Description

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>

Definition at line 55 of file ktempfile.h.

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Constructor & Destructor Documentation

KTempFile::KTempFile	(	QString	filePrefix = QString::null,
		QString	fileExtension = QString::null,
		int	mode = 0600
	)

Creates a temporary file with the name: <filePrefix><six letters><fileExtension>.

The default filePrefix is "$KDEHOME/tmp-$HOST/appname/" The default fileExtension is ".tmp"

Parameters:

	filePrefix	the prefix of the file name, or QString::null for the default value
	fileExtension	the extension of the prefix, or QString::null for the default value
	mode	the file permissions

Definition at line 60 of file ktempfile.cpp.

KTempFile::~KTempFile

(

)

The destructor closes the file.

If autoDelete is enabled the file gets unlinked as well.

Definition at line 129 of file ktempfile.cpp.

KTempFile::KTempFile

(

bool

)

[protected]

Constructor used by KSaveFile.

Definition at line 79 of file ktempfile.cpp.

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Member Function Documentation

bool KTempFile::close

(

)

Closes the file.

See status() for details about errors.

Returns:

true if successful, or false if an error has occurred.

Definition at line 253 of file ktempfile.cpp.

bool KTempFile::create	(	const QString &	filePrefix,
		const QString &	fileExtension,
		int	mode
	)			[protected]

For internal use only.

Create function used internally by KTempFile and KSaveFile

Definition at line 92 of file ktempfile.cpp.

QDataStream * KTempFile::dataStream

(

)

Returns a QDataStream for writing.

Returns:

QDataStream open for writing to the file, or 0 if opening the file failed

Definition at line 192 of file ktempfile.cpp.

QFile * KTempFile::file

(

)

Returns a QFile.

Returns:

A QFile open for writing to the file, or 0 if opening the file failed.

Definition at line 170 of file ktempfile.cpp.

FILE * KTempFile::fstream

(

)

Returns the FILE* of the temporary file.

Returns:

FILE* stream open for writing to the file, or 0 if opening the file failed

Definition at line 155 of file ktempfile.cpp.

int KTempFile::handle

(

)

const

An integer file descriptor open for writing to the file.

Returns:

The file descriptor, or a negative number if opening the file failed

Definition at line 149 of file ktempfile.cpp.

QString KTempFile::name

(

)

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.

Returns:

The name of the file, or QString::null if opening the file has failed or the file has been unlinked already.

Definition at line 143 of file ktempfile.cpp.

void KTempFile::setAutoDelete

(

bool

autoDelete

)

[inline]

Turn automatic deletion on or off.

Automatic deletion is off by default.

Parameters:

autoDelete

true to turn automatic deletion on

Definition at line 87 of file ktempfile.h.

void KTempFile::setError

(

int

error

)

[inline, protected]

Definition at line 198 of file ktempfile.h.

int KTempFile::status

(

)

const

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.

Returns:

the errno status, 0 means ok

Definition at line 137 of file ktempfile.cpp.

bool KTempFile::sync

(

)

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.

Returns:

true if successful, or false if an error has occurred.

Since:

3.3

Definition at line 216 of file ktempfile.cpp.

QTextStream * KTempFile::textStream

(

)

Returns the QTextStream for writing.

Returns:

QTextStream open for writing to the file, or 0 if opening the file failed

Definition at line 182 of file ktempfile.cpp.

void KTempFile::unlink

(

)

Unlinks the file from the directory.

The file is deleted once the last reader/writer closes it.

Definition at line 202 of file ktempfile.cpp.

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The documentation for this class was generated from the following files:

• ktempfile.h
• ktempfile.cpp