/usr/share/gtk-doc/html/cattle-1.0/io-handling.html is in libcattle-1.0-doc 1.2.2-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>I/O Handling: Cattle Reference Manual</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
<link rel="home" href="index.html" title="Cattle Reference Manual">
<link rel="up" href="ch04.html" title="Miscellaneous Topics">
<link rel="prev" href="ch04.html" title="Miscellaneous Topics">
<link rel="next" href="api-index-full.html" title="API Index">
<meta name="generator" content="GTK-Doc V1.25 (XML mode)">
<link rel="stylesheet" href="style.css" type="text/css">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="5"><tr valign="middle">
<td width="100%" align="left" class="shortcuts"></td>
<td><a accesskey="h" href="index.html"><img src="home.png" width="16" height="16" border="0" alt="Home"></a></td>
<td><a accesskey="u" href="ch04.html"><img src="up.png" width="16" height="16" border="0" alt="Up"></a></td>
<td><a accesskey="p" href="ch04.html"><img src="left.png" width="16" height="16" border="0" alt="Prev"></a></td>
<td><a accesskey="n" href="api-index-full.html"><img src="right.png" width="16" height="16" border="0" alt="Next"></a></td>
</tr></table>
<div class="refentry">
<a name="io-handling"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2><span class="refentrytitle">I/O Handling</span></h2>
<p>I/O Handling —
Explanation of the way Cattle performs I/O
</p>
</td>
<td class="gallery_image" valign="top" align="right"></td>
</tr></table></div>
<div class="refsect2">
<a name="id-1.5.2.3"></a><h3>I/O Basics</h3>
<p>
Cattle uses an I/O mechanism which allows for a huge degree
of flexibility while remaining relatively simple.
</p>
<p>
The I/O mechanism is based on callbacks: every time a
<a class="link" href="CattleInterpreter.html" title="CattleInterpreter">CattleInterpreter</a>
executes a Brainfuck instruction which requires some sort of
I/O, it invokes a user provided handler, and expects it to
perform the I/O operation.
</p>
<p>
Default I/O handlers are built into Cattle, so usually there
is no need to define a custom handler.
</p>
</div>
<hr>
<div class="refsect2">
<a name="id-1.5.2.4"></a><h3>Error reporting</h3>
<p>
Since I/O is not guaranteed to always be succesful, handlers
are provided a mean to report errors to the caller.
</p>
<p>
All handlers are passed a <a href="/usr/share/gtk-doc/html/glib/glib-Error-Reporting.html#GError">GError</a>
as last argument: if a handler fails, it is required to return
<a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#FALSE:CAPS">FALSE</a> and to fill the
error with detailed information.
</p>
<p>
If the hanler returns <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#TRUE:CAPS">TRUE</a>, but
the error is set, the operation is not considered succesful;
this is because handlers written in languages other than C might
not be able to both return a value and fill the error at the
same time.
</p>
</div>
<hr>
<div class="refsect2">
<a name="id-1.5.2.5"></a><h3>Output handler</h3>
<p>
Implementing an output handler is pretty straightforward: the
handler is passed a single <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint8">gint8</a>
and has to display it to the user in some way.
</p>
<p>
As an example, here is an handler which shows the output of
a Brainfuck program on a
GtkTextView:
</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>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</pre></td>
<td class="listing_code"><pre class="programlisting">gboolean
<span class="function">output_handler</span> <span class="gtkdoc opt">(</span>CattleInterpreter <span class="gtkdoc opt">*</span>interpreter<span class="gtkdoc opt">,</span>
gint8 output<span class="gtkdoc opt">,</span>
gpointer data<span class="gtkdoc opt">,</span>
GError <span class="gtkdoc opt">**</span>error<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
GtkTextView <span class="gtkdoc opt">*</span>view<span class="gtkdoc opt">;</span>
GtkTextBuffer <span class="gtkdoc opt">*</span>buffer<span class="gtkdoc opt">;</span>
GtkTextIter iter<span class="gtkdoc opt">;</span>
gchar text<span class="gtkdoc opt">[</span><span class="number">2</span><span class="gtkdoc opt">];</span>
view <span class="gtkdoc opt">=</span> <span class="function">GTK_TEXT_VIEW</span> <span class="gtkdoc opt">(</span>data<span class="gtkdoc opt">);</span>
<span class="comment">/* Get the buffer used by the GtkTextView */</span>
buffer <span class="gtkdoc opt">=</span> <span class="function">gtk_text_view_get_buffer</span> <span class="gtkdoc opt">(</span>view<span class="gtkdoc opt">);</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#g-object-ref">g_object_ref</a></span> <span class="gtkdoc opt">(</span>buffer<span class="gtkdoc opt">);</span>
<span class="comment">/* Get a reference to the end of the buffer */</span>
<span class="function">gtk_text_buffer_get_end_iter</span> <span class="gtkdoc opt">(</span>buffer<span class="gtkdoc opt">, &</span>iter<span class="gtkdoc opt">);</span>
<span class="comment">/* Create a string */</span>
text<span class="gtkdoc opt">[</span><span class="number">0</span><span class="gtkdoc opt">] = (</span>gchat<span class="gtkdoc opt">)</span> output<span class="gtkdoc opt">;</span>
text<span class="gtkdoc opt">[</span><span class="number">1</span><span class="gtkdoc opt">] =</span> <span class="string">'\0'</span><span class="gtkdoc opt">;</span>
<span class="comment">/* Insert the char at the end of the buffer */</span>
<span class="function">gtk_text_buffer_insert</span> <span class="gtkdoc opt">(</span>buffer<span class="gtkdoc opt">, &</span>iter<span class="gtkdoc opt">,</span> text<span class="gtkdoc opt">,</span> <span class="number">1</span><span class="gtkdoc opt">);</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#g-object-unref">g_object_unref</a></span> <span class="gtkdoc opt">(</span>buffer<span class="gtkdoc opt">);</span>
<span class="keyword">return</span> TRUE<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p>
The code assumes a GtkTextView
has been provided when the signal handler has been assigned to
the interpreter, like in the following code:
</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
2
3
4
5
6
7
8
9</pre></td>
<td class="listing_code"><pre class="programlisting">CattleInterpreter <span class="gtkdoc opt">*</span>interpreter<span class="gtkdoc opt">;</span>
GtkWidget <span class="gtkdoc opt">*</span>view<span class="gtkdoc opt">;</span>
interpreter <span class="gtkdoc opt">=</span> <span class="function"><a href="CattleInterpreter.html#cattle-interpreter-new">cattle_interpreter_new</a></span> <span class="gtkdoc opt">();</span>
view <span class="gtkdoc opt">=</span> <span class="function">gtk_text_view_new</span> <span class="gtkdoc opt">();</span>
<span class="function"><a href="CattleInterpreter.html#cattle-interpreter-set-output-handler">cattle_interpreter_set_output_handler</a></span> <span class="gtkdoc opt">(</span>interpreter<span class="gtkdoc opt">,</span>
output_handler<span class="gtkdoc opt">,</span>
<span class="gtkdoc opt">(</span>gpointer<span class="gtkdoc opt">)</span> view<span class="gtkdoc opt">);</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p>
Depending on the case, it may make sense for the application
to buffer an entire line of output, or even the whole output,
before sending it to its intended destination.
</p>
</div>
<hr>
<div class="refsect2">
<a name="id-1.5.2.6"></a><h3>Input handler</h3>
<p>
Here is an input handler which uses readline to fetch input
from the user:
</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>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</pre></td>
<td class="listing_code"><pre class="programlisting">gboolean
<span class="function">input_handler</span> <span class="gtkdoc opt">(</span>CattleInterpreter <span class="gtkdoc opt">*</span>interpreter<span class="gtkdoc opt">,</span>
gpointer data<span class="gtkdoc opt">,</span>
GError <span class="gtkdoc opt">**</span>error<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
CattleBuffer <span class="gtkdoc opt">*</span>buffer<span class="gtkdoc opt">;</span>
gchar <span class="gtkdoc opt">*</span>input<span class="gtkdoc opt">;</span>
gulong size<span class="gtkdoc opt">;</span>
<span class="comment">/* Read an input line using readline (no prompt) */</span>
input <span class="gtkdoc opt">=</span> <span class="function">readline</span> <span class="gtkdoc opt">(</span>NULL<span class="gtkdoc opt">);</span>
<span class="keyword">if</span> <span class="gtkdoc opt">(</span>input <span class="gtkdoc opt">!=</span> NULL<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
<span class="comment">/* A line of input has been read successfully, but it</span>
<span class="comment"> * needs to be copied into a CattleBuffer before</span>
<span class="comment"> * feeding it to the interpreter. */</span>
<span class="comment">/* Calculate the size of the CattleBuffer. readline</span>
<span class="comment"> * returns a null-terminated string with the trailing</span>
<span class="comment"> * newline stripped; a CattleBuffer doesn't need to be</span>
<span class="comment"> * null-terminated, but stripping the newline would mean</span>
<span class="comment"> * losing part of the input. We can just create a</span>
<span class="comment"> * CattleBuffer as big as the string, and replace the</span>
<span class="comment"> * trailing null byte with a newline. */</span>
size <span class="gtkdoc opt">=</span> <span class="function">strlen</span> <span class="gtkdoc opt">(</span>input<span class="gtkdoc opt">) +</span> <span class="number">1</span><span class="gtkdoc opt">;</span>
buffer <span class="gtkdoc opt">=</span> <span class="function"><a href="CattleBuffer.html#cattle-buffer-new">cattle_buffer_new</a></span> <span class="gtkdoc opt">(</span>size<span class="gtkdoc opt">);</span>
<span class="function"><a href="CattleBuffer.html#cattle-buffer-set-contents">cattle_buffer_set_contents</a></span> <span class="gtkdoc opt">(</span>buffer<span class="gtkdoc opt">,</span> input<span class="gtkdoc opt">);</span>
<span class="function"><a href="CattleBuffer.html#cattle-buffer-set-value">cattle_buffer_set_value</a></span> <span class="gtkdoc opt">(</span>buffer<span class="gtkdoc opt">,</span> size <span class="gtkdoc opt">-</span> <span class="number">1</span><span class="gtkdoc opt">,</span> <span class="string">'</span><span class="gtkdoc esc">\n</span><span class="string">'</span><span class="gtkdoc opt">);</span>
<span class="comment">/* The CattleBuffer now contains a copy of the input, so</span>
<span class="comment"> * the string returned by readline can be safely freed */</span>
<span class="function">free</span> <span class="gtkdoc opt">(</span>input<span class="gtkdoc opt">);</span>
<span class="function"><a href="CattleInterpreter.html#cattle-interpreter-feed">cattle_interpreter_feed</a></span> <span class="gtkdoc opt">(</span>interpreter<span class="gtkdoc opt">,</span> buffer<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">}</span>
<span class="keyword">else</span>
<span class="gtkdoc opt">{</span>
<span class="comment">/* readline returns NULL when the end of input has</span>
<span class="comment"> * been reached; to let the interpreter know no more</span>
<span class="comment"> * input is available, feed it an empty buffer */</span>
buffer <span class="gtkdoc opt">=</span> <span class="function"><a href="CattleBuffer.html#cattle-buffer-new">cattle_buffer_new</a></span> <span class="gtkdoc opt">(</span><span class="number">0</span><span class="gtkdoc opt">);</span>
<span class="function"><a href="CattleInterpreter.html#cattle-interpreter-feed">cattle_interpreter_feed</a></span> <span class="gtkdoc opt">(</span>interpreter<span class="gtkdoc opt">,</span> buffer<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">}</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#g-object-unref">g_object_unref</a></span> <span class="gtkdoc opt">(</span>buffer<span class="gtkdoc opt">);</span>
<span class="keyword">return</span> TRUE<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p>
Input works on a per-line basis: the handler must retrieve
a full line of input, including the trailing newline character,
and feed it to the interpreter.
</p>
<p>
If it is not possible to retrieve the whole line in a single
step, a part of it can be passed to the interpreter.
</p>
<p>
When the whole input has been consumed, the handler must feed
the interpreter an empty
<a class="link" href="CattleBuffer.html" title="CattleBuffer">CattleBuffer</a> to let it
know no more input is available.
</p>
</div>
<hr>
<div class="refsect2">
<a name="id-1.5.2.7"></a><h3>Debug</h3>
<p>
The debug handler is called whenever a <code class="code">#</code>
instruction is executed; the interpreter can be configured
to ignore this instruction, since it's not (strictly
speaking) part of the Brainfuck language.
</p>
<p>
The handler must display useful debugging information to
the developer; usually, this means dumping the contents of
the memory tape.
</p>
<p>
The following handler appends the contents of the tape to
a log file:
</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>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</pre></td>
<td class="listing_code"><pre class="programlisting">gboolean
<span class="function">debug_handler</span> <span class="gtkdoc opt">(</span>CattleInterpreter <span class="gtkdoc opt">*</span>interpreter<span class="gtkdoc opt">,</span>
gpointer data<span class="gtkdoc opt">,</span>
GError <span class="gtkdoc opt">**</span>error<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
CattleTape <span class="gtkdoc opt">*</span>tape<span class="gtkdoc opt">;</span>
gint8 value<span class="gtkdoc opt">;</span>
<span class="gtkdoc kwb">FILE</span><span class="gtkdoc opt">*</span> fp<span class="gtkdoc opt">;</span>
tape <span class="gtkdoc opt">=</span> <span class="function"><a href="CattleInterpreter.html#cattle-interpreter-get-tape">cattle_interpreter_get_tape</a></span> <span class="gtkdoc opt">(</span>interpreter<span class="gtkdoc opt">);</span>
<span class="comment">/* Save the current tape position */</span>
<span class="function"><a href="CattleTape.html#cattle-tape-push-bookmark">cattle_tape_push_bookmark</a></span> <span class="gtkdoc opt">(</span>tape<span class="gtkdoc opt">);</span>
fp <span class="gtkdoc opt">=</span> <span class="function">fopen</span> <span class="gtkdoc opt">(</span>LOG_FILE<span class="gtkdoc opt">,</span> <span class="string">"a"</span><span class="gtkdoc opt">);</span>
<span class="keyword">if</span> <span class="gtkdoc opt">(</span>fp <span class="gtkdoc opt">==</span> NULL<span class="gtkdoc opt">) {</span>
<span class="comment">/* Set the error, release resources and return */</span>
<span class="function"><a href="/usr/share/gtk-doc/html/glib/glib-Error-Reporting.html#g-set-error-literal">g_set_error_literal</a></span> <span class="gtkdoc opt">(</span>error<span class="gtkdoc opt">,</span>
CATTLE_INTERPRETER_ERROR<span class="gtkdoc opt">,</span>
CATTLE_INTERPRETER_ERROR_IO<span class="gtkdoc opt">,</span>
<span class="function">strerror</span> <span class="gtkdoc opt">(</span>errno<span class="gtkdoc opt">));</span>
<span class="function"><a href="CattleTape.html#cattle-tape-pop-bookmark">cattle_tape_pop_bookmark</a></span> <span class="gtkdoc opt">(</span>tape<span class="gtkdoc opt">);</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#g-object-unref">g_object_unref</a></span> <span class="gtkdoc opt">(</span>tape<span class="gtkdoc opt">);</span>
<span class="keyword">return</span> FALSE<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span>
<span class="comment">/* Rewind to the beginning of the tape */</span>
<span class="keyword">while</span> <span class="gtkdoc opt">(!</span><span class="function"><a href="CattleTape.html#cattle-tape-is-at-beginning">cattle_tape_is_at_beginning</a></span> <span class="gtkdoc opt">(</span>tape<span class="gtkdoc opt">)) {</span>
<span class="function"><a href="CattleTape.html#cattle-tape-move-left">cattle_tape_move_left</a></span> <span class="gtkdoc opt">(</span>tape<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">}</span>
<span class="function">fprintf</span> <span class="gtkdoc opt">(</span>fp<span class="gtkdoc opt">,</span> <span class="string">"[ "</span><span class="gtkdoc opt">);</span>
<span class="comment">/* Repeat until the end of the tape is reached */</span>
<span class="keyword">while</span> <span class="gtkdoc opt">(!</span><span class="function"><a href="CattleTape.html#cattle-tape-is-at-end">cattle_tape_is_at_end</a></span> <span class="gtkdoc opt">(</span>tape<span class="gtkdoc opt">)) {</span>
<span class="comment">/* Get the current value */</span>
value <span class="gtkdoc opt">=</span> <span class="function"><a href="CattleTape.html#cattle-tape-get-current-value">cattle_tape_get_current_value</a></span> <span class="gtkdoc opt">(</span>tape<span class="gtkdoc opt">);</span>
<span class="comment">/* Show printable values directly and non-printable</span>
<span class="comment"> * values as their decimal ASCII value */</span>
<span class="keyword">if</span> <span class="gtkdoc opt">(</span>value <span class="gtkdoc opt">>=</span> <span class="number">33</span> <span class="gtkdoc opt">&&</span> value <span class="gtkdoc opt"><=</span> <span class="number">126</span><span class="gtkdoc opt">) {</span>
<span class="function">fprintf</span> <span class="gtkdoc opt">(</span>fp<span class="gtkdoc opt">,</span> <span class="string">"%c "</span><span class="gtkdoc opt">,</span> value<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">}</span>
<span class="keyword">else</span> <span class="gtkdoc opt">{</span>
<span class="function">fprintf</span> <span class="gtkdoc opt">(</span>fp<span class="gtkdoc opt">,</span> <span class="string">"</span><span class="gtkdoc esc">\\</span><span class="string">%d "</span><span class="gtkdoc opt">, (</span>gint<span class="gtkdoc opt">)</span> value<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">}</span>
<span class="function"><a href="CattleTape.html#cattle-tape-move-right">cattle_tape_move_right</a></span> <span class="gtkdoc opt">(</span>tape<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">}</span>
<span class="function">fprintf</span> <span class="gtkdoc opt">(</span>fp<span class="gtkdoc opt">,</span> <span class="string">"]</span><span class="gtkdoc esc">\n</span><span class="string">"</span><span class="gtkdoc opt">);</span>
<span class="function">fclose</span> <span class="gtkdoc opt">(</span>fp<span class="gtkdoc opt">);</span>
<span class="comment">/* Restore the original tape position */</span>
<span class="function"><a href="CattleTape.html#cattle-tape-pop-bookmark">cattle_tape_pop_bookmark</a></span> <span class="gtkdoc opt">(</span>tape<span class="gtkdoc opt">);</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#g-object-unref">g_object_unref</a></span> <span class="gtkdoc opt">(</span>tape<span class="gtkdoc opt">);</span>
<span class="keyword">return</span> TRUE<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p>
After the handler has run, the tape must be in the same exact
state it was before the signal emission, including the
position. The best way to ensure it is to use
<a class="link" href="CattleTape.html#cattle-tape-push-bookmark" title="cattle_tape_push_bookmark ()">cattle_tape_push_bookmark()</a>
at the beginning of the handler and
<a class="link" href="CattleTape.html#cattle-tape-pop-bookmark" title="cattle_tape_pop_bookmark ()">cattle_tape_pop_bookmark()</a>
at the end.
</p>
</div>
</div>
<div class="footer">
<hr>Generated by GTK-Doc V1.25</div>
</body>
</html>
|