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< td align = "right" valign = "center" > < img src = "logo32.png" align = "right" width = "64" height = "32" border = "0" > < / td > < / tr > < / table > < h1 align = center > TQFile Class Reference< / h1 >
< p > The TQFile class is an I/O device that operates on files.
< a href = "#details" > More...< / a >
< p > Almost all the functions in this class are < a href = "threads.html#reentrant" > reentrant< / a > when TQt is built with thread support. The exceptions are < a href = "#setEncodingFunction" > < b > setEncodingFunction< / b > < / a > (), < a href = "#setDecodingFunction" > < b > setDecodingFunction< / b > < / a > (), and < a href = "#setErrorString" > < b > setErrorString< / b > < / a > ().
< / p > < p > < tt > #include < < a href = "qfile-h.html" > ntqfile.h< / a > > < / tt >
< p > Inherits < a href = "ntqiodevice.html" > TQIODevice< / a > .
< p > < a href = "qfile-members.html" > List of all member functions.< / a >
< h2 > Public Members< / h2 >
< ul >
< li class = fn > < a href = "#TQFile" > < b > TQFile< / b > < / a > ()< / li >
< li class = fn > < a href = "#TQFile-2" > < b > TQFile< / b > < / a > ( const TQString & name )< / li >
< li class = fn > < a href = "#~TQFile" > < b > ~TQFile< / b > < / a > ()< / li >
< li class = fn > TQString < a href = "#name" > < b > name< / b > < / a > () const< / li >
< li class = fn > void < a href = "#setName" > < b > setName< / b > < / a > ( const TQString & name )< / li >
< li class = fn > typedef TQCString (* < a href = "#EncoderFn" > < b > EncoderFn< / b > < / a > ) ( const TQString & fileName )< / li >
< li class = fn > typedef TQString (* < a href = "#DecoderFn" > < b > DecoderFn< / b > < / a > ) ( const TQCString & localfileName )< / li >
< li class = fn > bool < a href = "#exists-2" > < b > exists< / b > < / a > () const< / li >
< li class = fn > bool < a href = "#remove" > < b > remove< / b > < / a > ()< / li >
< li class = fn > virtual bool < a href = "#open" > < b > open< / b > < / a > ( int m )< / li >
< li class = fn > bool < a href = "#open-2" > < b > open< / b > < / a > ( int m, FILE * f )< / li >
< li class = fn > bool < a href = "#open-3" > < b > open< / b > < / a > ( int m, int f )< / li >
< li class = fn > virtual void < a href = "#close" > < b > close< / b > < / a > ()< / li >
< li class = fn > virtual void < a href = "#flush" > < b > flush< / b > < / a > ()< / li >
< li class = fn > virtual Offset < a href = "#size" > < b > size< / b > < / a > () const< / li >
< li class = fn > virtual bool < a href = "#atEnd" > < b > atEnd< / b > < / a > () const< / li >
< li class = fn > virtual Q_LONG < a href = "#readLine" > < b > readLine< / b > < / a > ( char * p, Q_ULONG maxlen )< / li >
< li class = fn > Q_LONG < a href = "#readLine-2" > < b > readLine< / b > < / a > ( TQString & s, Q_ULONG maxlen )< / li >
< li class = fn > virtual int < a href = "#getch" > < b > getch< / b > < / a > ()< / li >
< li class = fn > virtual int < a href = "#putch" > < b > putch< / b > < / a > ( int ch )< / li >
< li class = fn > virtual int < a href = "#ungetch" > < b > ungetch< / b > < / a > ( int ch )< / li >
< li class = fn > int < a href = "#handle" > < b > handle< / b > < / a > () const< / li >
< li class = fn > TQString < a href = "#errorString" > < b > errorString< / b > < / a > () const< / li >
< / ul >
< h2 > Static Public Members< / h2 >
< ul >
< li class = fn > TQCString < a href = "#encodeName" > < b > encodeName< / b > < / a > ( const TQString & fileName )< / li >
< li class = fn > TQString < a href = "#decodeName" > < b > decodeName< / b > < / a > ( const TQCString & localFileName )< / li >
< li class = fn > void < a href = "#setEncodingFunction" > < b > setEncodingFunction< / b > < / a > ( EncoderFn f )< / li >
< li class = fn > void < a href = "#setDecodingFunction" > < b > setDecodingFunction< / b > < / a > ( DecoderFn f )< / li >
< li class = fn > bool < a href = "#exists" > < b > exists< / b > < / a > ( const TQString & fileName )< / li >
< li class = fn > bool < a href = "#remove-2" > < b > remove< / b > < / a > ( const TQString & fileName )< / li >
< / ul >
< h2 > Important Inherited Members< / h2 >
< ul >
< li class = fn > virtual TQByteArray < a href = "#readAll" > < b > readAll< / b > < / a > ()< / li >
< / ul >
< h2 > Protected Members< / h2 >
< ul >
< li class = fn > void < a href = "#setErrorString" > < b > setErrorString< / b > < / a > ( const TQString & str )< / li >
< / ul >
< hr > < a name = "details" > < / a > < h2 > Detailed Description< / h2 >
The TQFile class is an I/O device that operates on files.
< p >
< p > TQFile is an I/O device for reading and writing binary and text
files. A TQFile may be used by itself or more conveniently with a
< a href = "ntqdatastream.html" > TQDataStream< / a > or < a href = "ntqtextstream.html" > TQTextStream< / a > .
< p > The file name is usually passed in the constructor but can be
changed with < a href = "#setName" > setName< / a > (). You can check for a file's existence with
< a href = "#exists" > exists< / a > () and remove a file with < a href = "#remove" > remove< / a > ().
< p > The file is opened with < a href = "#open" > open< / a > (), closed with < a href = "#close" > close< / a > () and flushed
with < a href = "#flush" > flush< / a > (). Data is usually read and written using TQDataStream
or TQTextStream, but you can read with < a href = "ntqiodevice.html#readBlock" > readBlock< / a > () and < a href = "#readLine" > readLine< / a > ()
and write with < a href = "ntqiodevice.html#writeBlock" > writeBlock< / a > (). TQFile also supports < a href = "#getch" > getch< / a > (),
< a href = "#ungetch" > ungetch< / a > () and < a href = "#putch" > putch< / a > ().
< p > The size of the file is returned by < a href = "#size" > size< / a > (). You can get the
current file position or move to a new file position using the
< a href = "ntqiodevice.html#at" > at< / a > () functions. If you've reached the end of the file, < a href = "#atEnd" > atEnd< / a > ()
returns TRUE. The file handle is returned by < a href = "#handle" > handle< / a > ().
< p > Here is a code fragment that uses < a href = "ntqtextstream.html" > TQTextStream< / a > to read a text file
line by line. It prints each line with a line number.
< pre >
< a href = "ntqstringlist.html" > TQStringList< / a > lines;
TQFile file( "file.txt" );
if ( file.< a href = "#open" > open< / a > ( IO_ReadOnly ) ) {
< a href = "ntqtextstream.html" > TQTextStream< / a > stream( & file );
< a href = "ntqstring.html" > TQString< / a > line;
int i = 1;
while ( !stream.< a href = "ntqtextstream.html#atEnd" > atEnd< / a > () ) {
line = stream.< a href = "ntqtextstream.html#readLine" > readLine< / a > (); // line of text excluding '\n'
printf( "%3d: %s\n", i++, line.< a href = "ntqstring.html#latin1" > latin1< / a > () );
lines += line;
}
file.< a href = "#close" > close< / a > ();
}
< / pre >
< p > Writing text is just as easy. The following example shows how to
write the data we read into the string list from the previous
example:
< pre >
TQFile file( "file.txt" );
if ( file.< a href = "#open" > open< / a > ( IO_WriteOnly ) ) {
< a href = "ntqtextstream.html" > TQTextStream< / a > stream( & file );
for ( TQStringList::Iterator it = lines.begin(); it != lines.end(); ++it )
stream < < *it < < "\n";
file.< a href = "#close" > close< / a > ();
}
< / pre >
< p > The < a href = "ntqfileinfo.html" > TQFileInfo< / a > class holds detailed information about a file, such
as access permissions, file dates and file types.
< p > The < a href = "ntqdir.html" > TQDir< / a > class manages directories and lists of file names.
< p > TQt uses Unicode file names. If you want to do your own I/O on Unix
systems you may want to use < a href = "#encodeName" > encodeName< / a > () (and < a href = "#decodeName" > decodeName< / a > ()) to
convert the file name into the local encoding.
< p >
< p > < p > See also < a href = "ntqdatastream.html" > TQDataStream< / a > , < a href = "ntqtextstream.html" > TQTextStream< / a > , and < a href = "io.html" > Input/Output and Networking< / a > .
< hr > < h2 > Member Type Documentation< / h2 >
< h3 class = fn > < a name = "DecoderFn" > < / a > TQFile::DecoderFn< / h3 >
< p > This is used by < a href = "#setDecodingFunction" > TQFile::setDecodingFunction< / a > ().
< h3 class = fn > < a name = "EncoderFn" > < / a > TQFile::EncoderFn< / h3 >
< p > This is used by < a href = "#setEncodingFunction" > TQFile::setEncodingFunction< / a > ().
< hr > < h2 > Member Function Documentation< / h2 >
< h3 class = fn > < a name = "TQFile" > < / a > TQFile::TQFile ()
< / h3 >
Constructs a TQFile with no name.
< h3 class = fn > < a name = "TQFile-2" > < / a > TQFile::TQFile ( const < a href = "ntqstring.html" > TQString< / a > & name )
< / h3 >
Constructs a TQFile with a file name < em > name< / em > .
< p > < p > See also < a href = "#setName" > setName< / a > ().
< h3 class = fn > < a name = "~TQFile" > < / a > TQFile::~TQFile ()
< / h3 >
Destroys a TQFile. Calls < a href = "#close" > close< / a > ().
< h3 class = fn > bool < a name = "atEnd" > < / a > TQFile::atEnd () const< tt > [virtual]< / tt >
< / h3 >
Returns TRUE if the end of file has been reached; otherwise returns FALSE.
If TQFile has not been < a href = "#open" > open< / a > ()'d, then the behavior is undefined.
< p > < p > See also < a href = "#size" > size< / a > ().
< p > Example: < a href = "distributor-example.html#x2655" > distributor/distributor.ui.h< / a > .
< p > Reimplemented from < a href = "ntqiodevice.html#atEnd" > TQIODevice< / a > .
< h3 class = fn > void < a name = "close" > < / a > TQFile::close ()< tt > [virtual]< / tt >
< / h3 >
Closes an open file.
< p > The file is not closed if it was opened with an existing file handle.
If the existing file handle is a < tt > FILE*< / tt > , the file is flushed.
If the existing file handle is an < tt > int< / tt > file descriptor, nothing
is done to the file.
< p > Some "write-behind" filesystems may report an unspecified error on
closing the file. These errors only indicate that something may
have gone wrong since the previous < a href = "#open" > open< / a > (). In such a case < a href = "ntqiodevice.html#status" > status< / a > ()
reports < a href = "ntqiodevice.html#status" > IO_UnspecifiedError< / a > after < a href = "#close" > close< / a > (), otherwise < a href = "ntqiodevice.html#status" > IO_Ok< / a > .
< p > < p > See also < a href = "#open" > open< / a > () and < a href = "#flush" > flush< / a > ().
< p > Examples: < a href = "tutorial2-07.html#x2590" > chart/chartform_files.cpp< / a > , < a href = "distributor-example.html#x2656" > distributor/distributor.ui.h< / a > , < a href = "helpviewer-example.html#x987" > helpviewer/helpwindow.cpp< / a > , < a href = "mdi-example.html#x2023" > mdi/application.cpp< / a > , < a href = "qdir-example.html#x1814" > qdir/qdir.cpp< / a > , < a href = "qwerty-example.html#x362" > qwerty/qwerty.cpp< / a > , and < a href = "outliner-example.html#x1914" > xml/outliner/outlinetree.cpp< / a > .
< p > Reimplemented from < a href = "ntqiodevice.html#close" > TQIODevice< / a > .
< h3 class = fn > < a href = "ntqstring.html" > TQString< / a > < a name = "decodeName" > < / a > TQFile::decodeName ( const < a href = "ntqcstring.html" > TQCString< / a > & localFileName )< tt > [static]< / tt >
< / h3 >
This does the reverse of < a href = "#encodeName" > TQFile::encodeName< / a > () using < em > localFileName< / em > .
< p > < p > See also < a href = "#setDecodingFunction" > setDecodingFunction< / a > ().
< p > Example: < a href = "distributor-example.html#x2657" > distributor/distributor.ui.h< / a > .
< h3 class = fn > < a href = "ntqcstring.html" > TQCString< / a > < a name = "encodeName" > < / a > TQFile::encodeName ( const < a href = "ntqstring.html" > TQString< / a > & fileName )< tt > [static]< / tt >
< / h3 >
When you use TQFile, < a href = "ntqfileinfo.html" > TQFileInfo< / a > , and < a href = "ntqdir.html" > TQDir< / a > to access the file system
with TQt, you can use Unicode file names. On Unix, these file names
are converted to an 8-bit encoding. If you want to do your own
file I/O on Unix, you should convert the file name using this
function. On Windows NT/2000, Unicode file names are supported
directly in the file system and this function should be avoided.
On Windows 95, non-Latin1 locales are not supported.
< p > By default, this function converts < em > fileName< / em > to the local 8-bit
encoding determined by the user's locale. This is sufficient for
file names that the user chooses. File names hard-coded into the
application should only use 7-bit ASCII filename characters.
< p > The conversion scheme can be changed using < a href = "#setEncodingFunction" > setEncodingFunction< / a > ().
This might be useful if you wish to give the user an option to
store file names in UTF-8, etc., but be aware that such file names
would probably then be unrecognizable when seen by other programs.
< p > < p > See also < a href = "#decodeName" > decodeName< / a > ().
< p > Example: < a href = "distributor-example.html#x2658" > distributor/distributor.ui.h< / a > .
< h3 class = fn > < a href = "ntqstring.html" > TQString< / a > < a name = "errorString" > < / a > TQFile::errorString () const
< / h3 >
Returns a human-readable description of the reason of an error that occurred
on the device. The error described by the string corresponds to changes of
< a href = "ntqiodevice.html#status" > TQIODevice::status< / a > (). If the status is reset, the error string is also reset.
< p > The returned strings are not translated with the < a href = "ntqobject.html#tr" > TQObject::tr< / a > () or
< a href = "ntqapplication.html#translate" > TQApplication::translate< / a > () functions. They are marked as translatable
strings in the "TQFile" context. Before you show the string to the user you
should translate it first, for example:
< p > < pre >
TQFile f( "address.dat" );
if ( !f.< a href = "#open" > open< / a > ( < a href = "ntqfile.html#open" > IO_ReadOnly< / a > ) {
TQMessageBox::< a href = "ntqmessagebox.html#critical" > critical< / a > (
this,
tr("Open failed"),
tr("Could not open file for reading: %1").arg( qApp-> < a href = "ntqapplication.html#translate" > translate< / a > ("TQFile",f.< a href = "#errorString" > errorString< / a > ()) )
);
return;
}
< / pre >
< p > < p > See also < a href = "ntqiodevice.html#status" > TQIODevice::status< / a > (), < a href = "ntqiodevice.html#resetStatus" > TQIODevice::resetStatus< / a > (), and < a href = "#setErrorString" > setErrorString< / a > ().
< h3 class = fn > bool < a name = "exists" > < / a > TQFile::exists ( const < a href = "ntqstring.html" > TQString< / a > & fileName )< tt > [static]< / tt >
< / h3 >
Returns TRUE if the file given by < em > fileName< / em > exists; otherwise
returns FALSE.
< p > Examples: < a href = "tutorial2-05.html#x2563" > chart/chartform.cpp< / a > , < a href = "dirview-example.html#x1674" > dirview/dirview.cpp< / a > , and < a href = "helpviewer-example.html#x988" > helpviewer/helpwindow.cpp< / a > .
< h3 class = fn > bool < a name = "exists-2" > < / a > TQFile::exists () const
< / h3 >
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
< p > Returns TRUE if this file exists; otherwise returns FALSE.
< p > < p > See also < a href = "#name" > name< / a > ().
< h3 class = fn > void < a name = "flush" > < / a > TQFile::flush ()< tt > [virtual]< / tt >
< / h3 >
Flushes the file buffer to the disk.
< p > < a href = "#close" > close< / a > () also flushes the file buffer.
< p > Reimplemented from < a href = "ntqiodevice.html#flush" > TQIODevice< / a > .
< h3 class = fn > int < a name = "getch" > < / a > TQFile::getch ()< tt > [virtual]< / tt >
< / h3 >
Reads a single byte/character from the file.
< p > Returns the byte/character read, or -1 if the end of the file has
been reached.
< p > < p > See also < a href = "#putch" > putch< / a > () and < a href = "#ungetch" > ungetch< / a > ().
< p > Reimplemented from < a href = "ntqiodevice.html#getch" > TQIODevice< / a > .
< h3 class = fn > int < a name = "handle" > < / a > TQFile::handle () const
< / h3 >
Returns the file handle of the file.
< p > This is a small positive integer, suitable for use with C library
functions such as fdopen() and fcntl(). On systems that use file
descriptors for sockets (ie. Unix systems, but not Windows) the handle
can be used with < a href = "ntqsocketnotifier.html" > TQSocketNotifier< / a > as well.
< p > If the file is not open or there is an error, < a href = "#handle" > handle< / a > () returns -1.
< p > < p > See also < a href = "ntqsocketnotifier.html" > TQSocketNotifier< / a > .
< h3 class = fn > < a href = "ntqstring.html" > TQString< / a > < a name = "name" > < / a > TQFile::name () const
< / h3 >
< p > Returns the name set by < a href = "#setName" > setName< / a > ().
< p > < p > See also < a href = "#setName" > setName< / a > () and < a href = "ntqfileinfo.html#fileName" > TQFileInfo::fileName< / a > ().
< h3 class = fn > bool < a name = "open" > < / a > TQFile::open ( int m )< tt > [virtual]< / tt >
< / h3 >
Opens the file specified by the file name currently set, using the
mode < em > m< / em > . Returns TRUE if successful, otherwise FALSE.
< p > <!-- index IO_Raw --> <!-- index IO_ReadOnly --> <!-- index IO_WriteOnly --> <!-- index IO_ReadWrite --> <!-- index IO_Append --> <!-- index IO_Truncate --> <!-- index IO_Translate -->
< p > The mode parameter < em > m< / em > must be a combination of the following flags:
< center > < table cellpadding = "4" cellspacing = "2" border = "0" >
< tr bgcolor = "#a2c511" > < th valign = "top" > Flag < th valign = "top" > Meaning
< tr bgcolor = "#f0f0f0" > < td valign = "top" > IO_Raw
< td valign = "top" > Raw (non-buffered) file access.
< tr bgcolor = "#d0d0d0" > < td valign = "top" > IO_ReadOnly
< td valign = "top" > Opens the file in read-only mode.
< tr bgcolor = "#f0f0f0" > < td valign = "top" > IO_WriteOnly
< td valign = "top" > Opens the file in write-only mode. If this flag is used
with another flag, e.g. < a href = "ntqfile.html#open" > IO_ReadOnly< / a > or < a href = "ntqfile.html#open" > IO_Raw< / a > or < a href = "ntqfile.html#open" > IO_Append< / a > , the file is < em > not< / em > truncated; but if used on
its own (or with < a href = "ntqfile.html#open" > IO_Truncate< / a > ), the file is truncated.
< tr bgcolor = "#d0d0d0" > < td valign = "top" > IO_ReadWrite
< td valign = "top" > Opens the file in read/write mode, equivalent to < tt > (IO_ReadOnly | IO_WriteOnly)< / tt > .
< tr bgcolor = "#f0f0f0" > < td valign = "top" > IO_Append
< td valign = "top" > Opens the file in append mode. (You must actually use < tt > (IO_WriteOnly | IO_Append)< / tt > to make the file writable and
to go into append mode.) This mode is very useful when you
want to write something to a log file. The file index is
set to the end of the file. Note that the result is
undefined if you position the file index manually using
< a href = "ntqiodevice.html#at" > at< / a > () in append mode.
< tr bgcolor = "#d0d0d0" > < td valign = "top" > IO_Truncate
< td valign = "top" > Truncates the file.
< tr bgcolor = "#f0f0f0" > < td valign = "top" > IO_Translate
< td valign = "top" > Enables carriage returns and linefeed translation for text
files under Windows.
< / table > < / center >
< p > The raw access mode is best when I/O is block-operated using a 4KB
block size or greater. Buffered access works better when reading
small portions of data at a time.
< p > < b > Warning:< / b > When working with buffered files, data may not be written
to the file at once. Call < a href = "#flush" > flush< / a > () to make sure that the data is
really written.
< p > < b > Warning:< / b > If you have a buffered file opened for both reading and
writing you must not perform an input operation immediately after
an output operation or vice versa. You should always call flush()
or a file positioning operation, e.g. at(), between input and
output operations, otherwise the buffer may contain garbage.
< p > If the file does not exist and < a href = "ntqfile.html#open" > IO_WriteOnly< / a > or < a href = "ntqfile.html#open" > IO_ReadWrite< / a >
is specified, it is created.
< p > Example:
< pre >
TQFile f1( "/tmp/data.bin" );
f1.< a href = "#open" > open< / a > ( IO_Raw | IO_ReadWrite );
TQFile f2( "readme.txt" );
f2.< a href = "#open" > open< / a > ( IO_ReadOnly | IO_Translate );
TQFile f3( "audit.log" );
f3.< a href = "#open" > open< / a > ( IO_WriteOnly | IO_Append );
< / pre >
< p > < p > See also < a href = "#name" > name< / a > (), < a href = "#close" > close< / a > (), < a href = "ntqiodevice.html#isOpen" > isOpen< / a > (), and < a href = "#flush" > flush< / a > ().
< p > Examples: < a href = "simple-application-example.html#x1548" > application/application.cpp< / a > , < a href = "tutorial2-07.html#x2591" > chart/chartform_files.cpp< / a > , < a href = "distributor-example.html#x2659" > distributor/distributor.ui.h< / a > , < a href = "helpviewer-example.html#x989" > helpviewer/helpwindow.cpp< / a > , < a href = "qdir-example.html#x1815" > qdir/qdir.cpp< / a > , < a href = "qwerty-example.html#x363" > qwerty/qwerty.cpp< / a > , and < a href = "outliner-example.html#x1915" > xml/outliner/outlinetree.cpp< / a > .
< p > Reimplemented from < a href = "ntqiodevice.html#open" > TQIODevice< / a > .
< h3 class = fn > bool < a name = "open-2" > < / a > TQFile::open ( int m, FILE * f )
< / h3 >
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
< p > Opens a file in the mode < em > m< / em > using an existing file handle < em > f< / em > .
Returns TRUE if successful, otherwise FALSE.
< p > Example:
< pre >
#include < stdio.h>
void printError( const char* msg )
{
TQFile f;
f.< a href = "#open" > open< / a > ( < a href = "ntqfile.html#open" > IO_WriteOnly< / a > , stderr );
f.< a href = "ntqiodevice.html#writeBlock" > writeBlock< / a > ( msg, tqstrlen(msg) ); // write to stderr
f.< a href = "#close" > close< / a > ();
}
< / pre >
< p > When a TQFile is opened using this function, < a href = "#close" > close< / a > () does not actually
close the file, only flushes it.
< p > < b > Warning:< / b > If < em > f< / em > is < tt > stdin< / tt > , < tt > stdout< / tt > , < tt > stderr< / tt > , you may not
be able to seek. See < a href = "ntqiodevice.html#isSequentialAccess" > TQIODevice::isSequentialAccess< / a > () for more
information.
< p > < p > See also < a href = "#close" > close< / a > ().
< h3 class = fn > bool < a name = "open-3" > < / a > TQFile::open ( int m, int f )
< / h3 >
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
< p > Opens a file in the mode < em > m< / em > using an existing file descriptor < em > f< / em > .
Returns TRUE if successful, otherwise FALSE.
< p > When a TQFile is opened using this function, < a href = "#close" > close< / a > () does not actually
close the file.
< p > The TQFile that is opened using this function, is automatically set to be in
raw mode; this means that the file input/output functions are slow. If you
run into performance issues, you should try to use one of the other open
functions.
< p > < b > Warning:< / b > If < em > f< / em > is one of 0 (stdin), 1 (stdout) or 2 (stderr), you may not
be able to seek. < a href = "#size" > size< / a > () is set to < tt > INT_MAX< / tt > (in limits.h).
< p > < p > See also < a href = "#close" > close< / a > ().
< h3 class = fn > int < a name = "putch" > < / a > TQFile::putch ( int ch )< tt > [virtual]< / tt >
< / h3 >
Writes the character < em > ch< / em > to the file.
< p > Returns < em > ch< / em > , or -1 if some error occurred.
< p > < p > See also < a href = "#getch" > getch< / a > () and < a href = "#ungetch" > ungetch< / a > ().
< p > Reimplemented from < a href = "ntqiodevice.html#putch" > TQIODevice< / a > .
< h3 class = fn > < a href = "qbytearray.html" > TQByteArray< / a > < a name = "readAll" > < / a > TQIODevice::readAll ()< tt > [virtual]< / tt >
< / h3 >
This convenience function returns all of the remaining data in the
device.
< h3 class = fn > Q_LONG < a name = "readLine" > < / a > TQFile::readLine ( char * p, Q_ULONG maxlen )< tt > [virtual]< / tt >
< / h3 >
Reads a line of text.
< p > Reads bytes from the file into the char* < em > p< / em > , until end-of-line
or < em > maxlen< / em > bytes have been read, whichever occurs first. Returns
the number of bytes read, or -1 if there was an error. Any
terminating newline is not stripped.
< p > This function is only efficient for buffered files. Avoid
< a href = "#readLine" > readLine< / a > () for files that have been opened with the < a href = "ntqfile.html#open" > IO_Raw< / a >
flag.
< p > < p > See also < a href = "ntqiodevice.html#readBlock" > readBlock< / a > () and < a href = "ntqtextstream.html#readLine" > TQTextStream::readLine< / a > ().
< p > Reimplemented from < a href = "ntqiodevice.html#readLine" > TQIODevice< / a > .
< h3 class = fn > Q_LONG < a name = "readLine-2" > < / a > TQFile::readLine ( < a href = "ntqstring.html" > TQString< / a > & s, Q_ULONG maxlen )
< / h3 >
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
< p > Reads a line of text.
< p > Reads bytes from the file into string < em > s< / em > , until end-of-line or
< em > maxlen< / em > bytes have been read, whichever occurs first. Returns
the number of bytes read, or -1 if there was an error, e.g. end of
file. Any terminating newline is not stripped.
< p > This function is only efficient for buffered files. Avoid using
< a href = "#readLine" > readLine< / a > () for files that have been opened with the < a href = "ntqfile.html#open" > IO_Raw< / a >
flag.
< p > Note that the string is read as plain Latin1 bytes, not Unicode.
< p > < p > See also < a href = "ntqiodevice.html#readBlock" > readBlock< / a > () and < a href = "ntqtextstream.html#readLine" > TQTextStream::readLine< / a > ().
< h3 class = fn > bool < a name = "remove" > < / a > TQFile::remove ()
< / h3 >
Removes the file specified by the file name currently set. Returns
TRUE if successful; otherwise returns FALSE.
< p > The file is closed before it is removed.
< h3 class = fn > bool < a name = "remove-2" > < / a > TQFile::remove ( const < a href = "ntqstring.html" > TQString< / a > & fileName )< tt > [static]< / tt >
< / h3 >
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
< p > Removes the file < em > fileName< / em > .
Returns TRUE if successful, otherwise FALSE.
< h3 class = fn > void < a name = "setDecodingFunction" > < / a > TQFile::setDecodingFunction ( < a href = "ntqfile.html#DecoderFn" > DecoderFn< / a > f )< tt > [static]< / tt >
< / h3 > < p > < b > Warning:< / b > This function is < i > not< / i > < a href = "threads.html#reentrant" > reentrant< / a > .< / p >
< p > Sets the function for decoding 8-bit file names to < em > f< / em > . The
default uses the locale-specific 8-bit encoding.
< p > < p > See also < a href = "#encodeName" > encodeName< / a > () and < a href = "#decodeName" > decodeName< / a > ().
< h3 class = fn > void < a name = "setEncodingFunction" > < / a > TQFile::setEncodingFunction ( < a href = "ntqfile.html#EncoderFn" > EncoderFn< / a > f )< tt > [static]< / tt >
< / h3 > < p > < b > Warning:< / b > This function is < i > not< / i > < a href = "threads.html#reentrant" > reentrant< / a > .< / p >
< p > Sets the function for encoding Unicode file names to < em > f< / em > . The
default encodes in the locale-specific 8-bit encoding.
< p > < p > See also < a href = "#encodeName" > encodeName< / a > ().
< h3 class = fn > void < a name = "setErrorString" > < / a > TQFile::setErrorString ( const < a href = "ntqstring.html" > TQString< / a > & str )< tt > [protected]< / tt >
< / h3 > < p > < b > Warning:< / b > This function is < i > not< / i > < a href = "threads.html#reentrant" > reentrant< / a > .< / p >
< p > Sets the error string returned by the < a href = "#errorString" > errorString< / a > () function to < em > str< / em > .
< p > < p > See also < a href = "#errorString" > errorString< / a > () and < a href = "ntqiodevice.html#status" > TQIODevice::status< / a > ().
< h3 class = fn > void < a name = "setName" > < / a > TQFile::setName ( const < a href = "ntqstring.html" > TQString< / a > & name )
< / h3 >
Sets the name of the file to < em > name< / em > . The name can have no path, a
relative path or an absolute absolute path.
< p > Do not call this function if the file has already been opened.
< p > If the file name has no path or a relative path, the path used
will be whatever the application's current directory path is
< em > at the time of the < a href = "#open" > open< / a > ()< / em > call.
< p > Example:
< pre >
TQFile file;
TQDir::< a href = "ntqdir.html#setCurrent" > setCurrent< / a > ( "/tmp" );
file.< a href = "#setName" > setName< / a > ( "readme.txt" );
TQDir::< a href = "ntqdir.html#setCurrent" > setCurrent< / a > ( "/home" );
file.< a href = "#open" > open< / a > ( < a href = "ntqfile.html#open" > IO_ReadOnly< / a > ); // opens "/home/readme.txt" under Unix
< / pre >
< p > Note that the directory separator "/" works for all operating
systems supported by TQt.
< p > < p > See also < a href = "#name" > name< / a > (), < a href = "ntqfileinfo.html" > TQFileInfo< / a > , and < a href = "ntqdir.html" > TQDir< / a > .
< h3 class = fn > < a href = "ntqiodevice.html#Offset" > Offset< / a > < a name = "size" > < / a > TQFile::size () const< tt > [virtual]< / tt >
< / h3 >
Returns the file size.
< p > See also < a href = "ntqiodevice.html#at" > at< / a > ().
< p > Example: < a href = "statistics-example.html#x2781" > table/statistics/statistics.cpp< / a > .
< p > Reimplemented from < a href = "ntqiodevice.html#size" > TQIODevice< / a > .
< h3 class = fn > int < a name = "ungetch" > < / a > TQFile::ungetch ( int ch )< tt > [virtual]< / tt >
< / h3 >
Puts the character < em > ch< / em > back into the file and decrements the
index if it is not zero.
< p > This function is normally called to "undo" a < a href = "#getch" > getch< / a > () operation.
< p > Returns < em > ch< / em > , or -1 if an error occurred.
< p > < p > See also < a href = "#getch" > getch< / a > () and < a href = "#putch" > putch< / a > ().
< p > Reimplemented from < a href = "ntqiodevice.html#ungetch" > TQIODevice< / a > .
<!-- eof -->
< hr > < p >
This file is part of the < a href = "index.html" > TQt toolkit< / a > .
Copyright © 1995-2007
< a href = "http://www.trolltech.com/" > Trolltech< / a > . All Rights Reserved.< p > < address > < hr > < div align = center >
< table width = 100% cellspacing = 0 border = 0 > < tr >
< td > Copyright © 2007
< a href = "troll.html" > Trolltech< / a > < td align = center > < a href = "trademarks.html" > Trademarks< / a >
< td align = right > < div align = right > TQt 3.3.8< / div >
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