org.kde.koala
Class KTempFile

java.lang.Object
  extended by org.kde.koala.KTempFile
All Implemented Interfaces:
org.kde.qt.QtSupport

public class KTempFile
extends java.lang.Object
implements org.kde.qt.QtSupport

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

Constructor Summary
  KTempFile()
           
  KTempFile(boolean arg1)
          Constructor used by KSaveFile
protected KTempFile(java.lang.Class dummy)
           
  KTempFile(java.lang.String filePrefix)
           
  KTempFile(java.lang.String filePrefix, java.lang.String fileExtension)
           
  KTempFile(java.lang.String filePrefix, java.lang.String fileExtension, int mode)
          Creates a temporary file with the name: \\\ The default filePrefix is "$KDEHOME/tmp-$HOST/appname/" The default fileExtension is ".tmp"
 
Method Summary
 boolean close()
          Closes the file.
protected  boolean create(java.lang.String filePrefix, java.lang.String fileExtension, int mode)
          Create function used internally by KTempFile and KSaveFile
 org.kde.qt.QDataStream dataStream()
          Returns a QDataStream for writing.
 void dispose()
          Delete the wrapped C++ instance ahead of finalize()
 org.kde.qt.QFile file()
          Returns a QFile.
protected  void finalize()
          Deletes the wrapped C++ instance
 int handle()
          An integer file descriptor open for writing to the file
 boolean isDisposed()
          Has the wrapped C++ instance been deleted?
 java.lang.String name()
          Returns the full path and name of the file.
 void setAutoDelete(boolean autoDelete)
          Turn automatic deletion on or off.
protected  void setError(int error)
           
 int status()
          Returns the status of the file based on errno.
 boolean sync()
          Flushes file to disk (fsync).
 org.kde.qt.QTextStream textStream()
          Returns the QTextStream for writing.
 void unlink()
          Unlinks the file from the directory.
 
Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

KTempFile

protected KTempFile(java.lang.Class dummy)

KTempFile

public KTempFile(java.lang.String filePrefix,
                 java.lang.String fileExtension,
                 int mode)
Creates a temporary file with the name: \\\ The default filePrefix is "$KDEHOME/tmp-$HOST/appname/" The default fileExtension is ".tmp"

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

KTempFile

public KTempFile(java.lang.String filePrefix,
                 java.lang.String fileExtension)

KTempFile

public KTempFile(java.lang.String filePrefix)

KTempFile

public KTempFile()

KTempFile

public KTempFile(boolean arg1)
Constructor used by KSaveFile

Method Detail

setAutoDelete

public void setAutoDelete(boolean autoDelete)
Turn automatic deletion on or off. Automatic deletion is off by default.

Parameters:
autoDelete - true to turn automatic deletion on

status

public int status()
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

name

public java.lang.String name()
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 null if opening the file has failed or the file has been unlinked already.

handle

public int handle()
An integer file descriptor open for writing to the file

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

textStream

public org.kde.qt.QTextStream textStream()
Returns the QTextStream for writing.

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

dataStream

public org.kde.qt.QDataStream dataStream()
Returns a QDataStream for writing.

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

file

public org.kde.qt.QFile file()
Returns a QFile.

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

unlink

public void unlink()
Unlinks the file from the directory. The file is deleted once the last reader/writer closes it.


sync

public boolean 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.

close

public boolean close()
Closes the file. See status() for details about errors.

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

create

protected boolean create(java.lang.String filePrefix,
                         java.lang.String fileExtension,
                         int mode)
Create function used internally by KTempFile and KSaveFile


setError

protected void setError(int error)

finalize

protected void finalize()
                 throws java.lang.InternalError
Deletes the wrapped C++ instance

Overrides:
finalize in class java.lang.Object
Throws:
java.lang.InternalError

dispose

public void dispose()
Delete the wrapped C++ instance ahead of finalize()


isDisposed

public boolean isDisposed()
Has the wrapped C++ instance been deleted?