This file is indexed.

/usr/share/doc/libbobcat4-dev/man/signal.3.html is in libbobcat-dev 4.04.00-1.

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
<!DOCTYPE html><html><head>
<meta charset="UTF-8">
<title>FBB::Signal</title>
<style type="text/css">
    figure {text-align: center;}
    img {vertical-align: center;}
</style>
<link rev="made" href="mailto:Frank B. Brokken: f.b.brokken@rug.nl">
</head>
<body text="#27408B" bgcolor="#FFFAF0">
<hr/>
<h1 id="title">FBB::Signal</h1>
<h2 id="author">libbobcat-dev_4.04.00-x.tar.gz</h2>
<h2 id="date">2005-2016</h2>

<!DOCTYPE html><html><head>
<meta charset="UTF-8">
<style type="text/css">
    figure {text-align: center;}
    img {vertical-align: center;}
    figure {text-align: center;}
    img {vertical-align: center;}
</style>
<link rev="made" href="mailto:Frank B. Brokken: f.b.brokken@rug.nl">
</head>
<body text="#27408B" bgcolor="#FFFAF0">
<hr/>
<h1 id="title"></h1>

<!DOCTYPE html><html><head>
<meta charset="UTF-8">
<title>FBB::Signal(3bobcat)</title>
<style type="text/css">
    figure {text-align: center;}
    img {vertical-align: center;}
    figure {text-align: center;}
    img {vertical-align: center;}
    figure {text-align: center;}
    img {vertical-align: center;}
</style>
<link rev="made" href="mailto:Frank B. Brokken: f.b.brokken@rug.nl">
</head>
<body text="#27408B" bgcolor="#FFFAF0">
<hr/>
<h1 id="title">FBB::Signal(3bobcat)</h1>
<h2 id="author">libbobcat-dev_4.04.00-x.tar.gz signal handler</h2>
<h2 id="date">2005-2016</h2>


<p>
<h2 >NAME</h2>FBB::Signal - Signal Handler
<p>
<h2 >SYNOPSIS</h2>
    <strong >#include &lt;bobcat/signal&gt;</strong><br/>
    Linking option: <em >-lbobcat</em> 
<p>
<h2 >DESCRIPTION</h2>
<p>
Signals have the well known drawback that signals arrive free of
context. E.g., assume a program runs a flow control loop like this:
    <pre>

void Class::run()
{
    while (d_continue)
        handleTasks();
    cleanup();
}
    
</pre>

    then if the program needs to recognize  a termination signal then the
typical signal handler looks like this:
    <pre>

void signalHandler(int signal)
{
    // perform required actions
}
    
</pre>

    Since the <em >signalHandler</em> is called asynchronically, there is no context
available, and the usual way of communicating between objects and signal
handlers is via static variables, like this:
    <pre>

// declared as static bool s_continue;
bool Class::s_continue = true; 

void Class::run()
{
    while (s_continue)
        handleTasks();
    cleanup();
}

// declared as static void signalHander(int signal);
void Class::signalHandler(int signal)
{
    s_continue = false;
}
    
</pre>

    The class <em >Signal</em> allows the signal handler to operate in the context
of a class. The advantage of this is that static data members are no longer
required and that the signal may be used to control data members of individual
objects. 
<p>
The signal is now handled by an object, whose class must define a member 
        <pre>

    void signalHandler(size_t signum) override;
        
</pre>

    and this function is responsible for handling the received signal. Since
it is a member function it may affect its object's local variables and it may
call its object's member functions. Static data members are not required
anymore (see below for an example).
<p>
Note that, as the signal may arrive at unpredicable times data members
that can be modified by <em >signalHandler</em> should be declared using the
<em >volatile</em> modifier. Moreover, data that can be modified by
the <em >signalHandler</em> member and by other class members should be protected
by <em >mutexes</em> (cf. the <strong >C++-11</strong> class <em >std::mutex</em> or
<strong >pthread_mutex_lock</strong>(3posix)). 
<p>
<h2 >NAMESPACE</h2>
    <strong >FBB</strong><br/>
    All constructors, members, operators and manipulators, mentioned in this
man-page, are defined in the namespace <strong >FBB</strong>.
<p>
<h2 >INHERITS FROM</h2>
    <em >Signal</em> is not derived from other classes, but the classes for which
signals must be handled by <em >Signal</em> must themselves publicly be derived from
the class <em >FBB::SignalHandler</em> and must implement a member 
        <pre>

    void signalHandler(size_t signum) override;
        
</pre>

    handling the received signal.
<p>
<h2 >CONSTRUCTORS AND OVERLOADED OPERATORS</h2>
    <em >Signal</em> is defined as a <em >singleton</em>, and does not offer public or
protected constructors, nor does it offer overloaded operators.
<p>
<h2 >STATIC MEMBER FUNCTION</h2>
    <ul>
    <li> <strong >static Signal &amp;instance()</strong>:<br/><br/>
        This static member can be used to access a reference to the program's
single <em >Signal</em> object.
    </ul>
<p>
<h2 >MEMBER FUNCTIONS</h2>
    All of <em >Signal</em>'s member functions can only be called through a
reference to the program's <em >Signal</em> object, returning a reference to the
program's single <em >Signal</em> object:
    <ul>
    <li> <strong >void add(size_t signum, SignalHandler &amp;object)</strong>:<br/><br/> 
       <em >SignalHandler object</em> is activated on arrival of signal
        <em >signum</em>. If multiple <em >SignalHandler</em> objects must be called then
        multiple <em >Signal::add</em> calls can be provided, and the various
        <em >SignalHandler::signalHandler</em> members are called in the same
        sequence as their respective <em >Signal::add</em> calls. If one of the
        earlier <em >signalHandler</em> members terminates the program then later
        <em >signalHandler</em> members are not activated anymore. If
        <em >Signal::add</em> is called by, e.g., an object's constructor, then its
        destructor should call <em >Signal::remove</em> to prevent the object's
        signal handler from being called after its destruction.
    <li> <strong >void remove(size_t signum, SignalHandler &amp;object)</strong>:<br/><br/> 
       <em >SignalHandler object</em> for signal <em >signum</em> is removed from the
        <em >Signal</em> object. It is the responsibility of <em >object</em> to
        deregister itself from <em >Signal</em> just before <em >object</em> goes out of
        scope. Objects can only deregister themselves if they've previously
        registered themselves using <em >add</em>.
    <li> <strong >void ignore(size_t signum)</strong>:<br/><br/>
       Any previously installed <em >SignalHandler</em> object is no longer
        activated on arrival of signal <em >signum</em>. In addition, if possible,
        signal <em >signum</em> is completely ignored (some signals cannot be
        caught, blocked, of ignored, like <em >SIGKILL</em> and <em >SIGSTOP</em>
        (cf. <strong >signal</strong>(7))).
    <li> <strong >void reset(size_t signum)</strong>:<br/><br/>
       Any previously installed <em >SignalHandler</em> object is no longer
        activated on arrival of signal <em >signum</em>. In addition, the default
        action the program takes on arrival of signal <em >signum</em> is
        reinstalled (cf. <strong >signal</strong>(7)).
    </ul>
<p>
If the <em >signum</em> value that is passed to <em >Signal</em>'s members is not a
defined signal value, then an <strong >FBB::Exception</strong> exception is thrown. 
<p>
<h2 >EXAMPLE</h2>
    <pre >
#include &lt;sys/types.h&gt;
#include &lt;unistd.h&gt;

#include &lt;iostream&gt;

#include "../signal"

class SignalDemo: public FBB::SignalHandler
{
    volatile size_t d_signal;
    volatile bool d_continue;
    pid_t d_pid;

    public:
        SignalDemo();
        void run();

    private:
        void signalHandler(size_t signum) override;
};

using namespace std;
using namespace FBB;

SignalDemo::SignalDemo()
:
    d_signal(0),
    d_continue(true),
    d_pid(getpid())
{}

void SignalDemo::run()
{
    while (d_continue)
    {
        cout &lt;&lt; "Send a SIGINT (2) or SIGTERM (15) ... to process " &lt;&lt; 
                    d_pid &lt;&lt; endl;

        sleep(1);
    }
    cout &lt;&lt; "Ending `run' after receiving signal " &lt;&lt; d_signal &lt;&lt; endl;
}

void SignalDemo::signalHandler(size_t signal)
{
    if (signal == SIGINT)
        cout &lt;&lt; "Process " &lt;&lt; d_pid &lt;&lt; " received SIGINT" &lt;&lt; endl;
    else if (signal == SIGTERM)
    {
        cout &lt;&lt; "Process " &lt;&lt; d_pid &lt;&lt; " received SIGTERM" &lt;&lt; endl;
        d_signal = SIGTERM;
        d_continue = false;
    }
}

int main()
{
    SignalDemo signalDemo;

    Signal::instance().add(SIGINT, signalDemo);
    Signal::instance().add(SIGTERM, signalDemo);

    signalDemo.run();
}





</pre>

<p>
<h2 >FILES</h2>
    <em >bobcat/signal</em> - defines the class interface
<p>
<h2 >SEE ALSO</h2>
    <strong >bobcat</strong>(7), <strong >pthread_mutex_lock</strong>(3posix), <strong >signal</strong>(7),<br/>
    and the <strong >C++-11</strong> class <em >std::mutex</em>.
<p>
<h2 >BUGS</h2>
    None Reported.
<p>

<h2 >DISTRIBUTION FILES</h2>
    <ul>
    <li> <em >bobcat_4.04.00-x.dsc</em>: detached signature;
    <li> <em >bobcat_4.04.00-x.tar.gz</em>: source archive;
    <li> <em >bobcat_4.04.00-x_i386.changes</em>: change log;
    <li> <em >libbobcat1_4.04.00-x_*.deb</em>: debian package holding the
            libraries;
    <li> <em >libbobcat1-dev_4.04.00-x_*.deb</em>: debian package holding the
            libraries, headers and manual pages;
    <li> <em >http://sourceforge.net/projects/bobcat</em>: public archive location;
    </ul>
<p>
<h2 >BOBCAT</h2>
    Bobcat is an acronym of `Brokken's Own Base Classes And Templates'.
<p>
<h2 >COPYRIGHT</h2>
    This is free software, distributed under the terms of the 
    GNU General Public License (GPL).
<p>
<h2 >AUTHOR</h2>
    Frank B. Brokken (<strong >f.b.brokken@rug.nl</strong>).
<p>