1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/src/tools/qfile.cpp:77 -->
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>TQFile Class</title>
<style type="text/css"><!--
fn { margin-left: 1cm; text-indent: -1cm; }
a:link { color: #004faf; text-decoration: none }
a:visited { color: #672967; text-decoration: none }
body { background: #ffffff; color: black; }
--></style>
</head>
<body>
<table border="0" cellpadding="0" cellspacing="0" width="100%">
<tr bgcolor="#E5E5E5">
<td valign=center>
<a href="index.html">
<font color="#004faf">Home</font></a>
| <a href="classes.html">
<font color="#004faf">All Classes</font></a>
| <a href="mainclasses.html">
<font color="#004faf">Main Classes</font></a>
| <a href="annotated.html">
<font color="#004faf">Annotated</font></a>
| <a href="groups.html">
<font color="#004faf">Grouped Classes</font></a>
| <a href="functions.html">
<font color="#004faf">Functions</font></a>
</td>
<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>
</table></div></address></body>
</html>
|
