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
|
<!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/network/tqdns.cpp:1597 -->
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>TQDns 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>TQDns Class Reference<br><small>[<a href="network.html">network module</a>]</small></h1>
<p>The TQDns class provides asynchronous DNS lookups.
<a href="#details">More...</a>
<p><tt>#include <<a href="tqdns-h.html">tqdns.h</a>></tt>
<p>Inherits <a href="tqobject.html">TQObject</a>.
<p><a href="tqdns-members.html">List of all member functions.</a>
<h2>Public Members</h2>
<ul>
<li class=fn>enum <a href="#RecordType-enum"><b>RecordType</b></a> { None, A, Aaaa, Mx, Srv, Cname, Ptr, Txt }</li>
<li class=fn><a href="#TQDns"><b>TQDns</b></a> ()</li>
<li class=fn><a href="#TQDns-2"><b>TQDns</b></a> ( const TQString & label, RecordType rr = A )</li>
<li class=fn><a href="#TQDns-3"><b>TQDns</b></a> ( const TQHostAddress & address, RecordType rr = Ptr )</li>
<li class=fn>virtual <a href="#~TQDns"><b>~TQDns</b></a> ()</li>
<li class=fn>virtual void <a href="#setLabel"><b>setLabel</b></a> ( const TQString & label )</li>
<li class=fn>virtual void <a href="#setLabel-2"><b>setLabel</b></a> ( const TQHostAddress & address )</li>
<li class=fn>TQString <a href="#label"><b>label</b></a> () const</li>
<li class=fn>virtual void <a href="#setRecordType"><b>setRecordType</b></a> ( RecordType rr = A )</li>
<li class=fn>RecordType <a href="#recordType"><b>recordType</b></a> () const</li>
<li class=fn>bool <a href="#isWorking"><b>isWorking</b></a> () const</li>
<li class=fn>TQValueList<TQHostAddress> <a href="#addresses"><b>addresses</b></a> () const</li>
<li class=fn>TQValueList<MailServer> <a href="#mailServers"><b>mailServers</b></a> () const</li>
<li class=fn>TQValueList<Server> <a href="#servers"><b>servers</b></a> () const</li>
<li class=fn>TQStringList <a href="#hostNames"><b>hostNames</b></a> () const</li>
<li class=fn>TQStringList <a href="#texts"><b>texts</b></a> () const</li>
<li class=fn>TQString <a href="#canonicalName"><b>canonicalName</b></a> () const</li>
<li class=fn>TQStringList <a href="#qualifiedNames"><b>qualifiedNames</b></a> () const</li>
</ul>
<h2>Signals</h2>
<ul>
<li class=fn>void <a href="#resultsReady"><b>resultsReady</b></a> ()</li>
</ul>
<hr><a name="details"></a><h2>Detailed Description</h2>
The TQDns class provides asynchronous DNS lookups.
<p>
<p> Both Windows and Unix provide synchronous DNS lookups; Windows
provides some asynchronous support too. At the time of writing
neither operating system provides asynchronous support for
anything other than hostname-to-address mapping.
<p> TQDns rectifies this shortcoming, by providing asynchronous caching
lookups for the record types that we expect modern GUI
applications to need in the near future.
<p> The class is <em>not</em> straightforward to use (although it is much
simpler than the native APIs); <a href="tqsocket.html">TQSocket</a> provides much easier to use
TCP connection facilities. The aim of TQDns is to provide a correct
and small API to the DNS and nothing more. (We use "correctness"
to mean that the DNS information is correctly cached, and
correctly timed out.)
<p> The API comprises a constructor, functions to set the DNS node
(the domain in DNS terminology) and record type (<a href="#setLabel">setLabel</a>() and
<a href="#setRecordType">setRecordType</a>()), the corresponding get functions, an <a href="#isWorking">isWorking</a>()
function to determine whether TQDns is working or reading, a
<a href="#resultsReady">resultsReady</a>() signal and query functions for the result.
<p> There is one query function for each RecordType, namely
<a href="#addresses">addresses</a>(), <a href="#mailServers">mailServers</a>(), <a href="#servers">servers</a>(), <a href="#hostNames">hostNames</a>() and <a href="#texts">texts</a>().
There are also two generic query functions: <a href="#canonicalName">canonicalName</a>()
returns the name you'll presumably end up using (the exact meaning
of this depends on the record type) and <a href="#qualifiedNames">qualifiedNames</a>() returns a
list of the fully qualified names <a href="#label">label</a>() maps to.
<p> <p>See also <a href="tqsocket.html">TQSocket</a> and <a href="io.html">Input/Output and Networking</a>.
<hr><h2>Member Type Documentation</h2>
<h3 class=fn><a name="RecordType-enum"></a>TQDns::RecordType</h3>
<p> This enum type defines the record types TQDns can handle. The DNS
provides many more; these are the ones we've judged to be in
current use, useful for GUI programs and important enough to
support right away:
<ul>
<li><tt>TQDns::None</tt> - No information. This exists only so that TQDns can
have a default.
<li><tt>TQDns::A</tt> - IPv4 addresses. By far the most common type.
<li><tt>TQDns::Aaaa</tt> - IPv6 addresses. So far mostly unused.
<li><tt>TQDns::Mx</tt> - Mail eXchanger names. Used for mail delivery.
<li><tt>TQDns::Srv</tt> - SeRVer names. Generic record type for finding
servers. So far mostly unused.
<li><tt>TQDns::Cname</tt> - Canonical names. Maps from nicknames to the true
name (the canonical name) for a host.
<li><tt>TQDns::Ptr</tt> - name PoinTeRs. Maps from IPv4 or IPv6 addresses to hostnames.
<li><tt>TQDns::Txt</tt> - arbitrary TeXT for domains.
</ul><p> We expect that some support for the
<a href="http://www.dns.net/dnsrd/rfc/rfc2535.html">RFC-2535</a>
extensions will be added in future versions.
<hr><h2>Member Function Documentation</h2>
<h3 class=fn><a name="TQDns"></a>TQDns::TQDns ()
</h3>
Constructs a DNS query object with invalid settings for both the
label and the search type.
<h3 class=fn><a name="TQDns-2"></a>TQDns::TQDns ( const <a href="tqstring.html">TQString</a> & label, <a href="tqdns.html#RecordType-enum">RecordType</a> rr = A )
</h3>
Constructs a DNS query object that will return record type <em>rr</em>
information about <em>label</em>.
<p> The DNS lookup is started the next time the application enters the
event loop. When the result is found the signal <a href="#resultsReady">resultsReady</a>() is
emitted.
<p> <em>rr</em> defaults to <a href="#RecordType-enum">A</a>, IPv4 addresses.
<h3 class=fn><a name="TQDns-3"></a>TQDns::TQDns ( const <a href="tqhostaddress.html">TQHostAddress</a> & address, <a href="tqdns.html#RecordType-enum">RecordType</a> rr = Ptr )
</h3>
Constructs a DNS query object that will return record type <em>rr</em>
information about host address <em>address</em>. The label is set to the
IN-ADDR.ARPA domain name. This is useful in combination with the
<a href="#RecordType-enum">Ptr</a> record type (e.g. if you want to look up a hostname for a
given address).
<p> The DNS lookup is started the next time the application enters the
event loop. When the result is found the signal <a href="#resultsReady">resultsReady</a>() is
emitted.
<p> <em>rr</em> defaults to <a href="#RecordType-enum">Ptr</a>, that maps addresses to hostnames.
<h3 class=fn><a name="~TQDns"></a>TQDns::~TQDns ()<tt> [virtual]</tt>
</h3>
Destroys the DNS query object and frees its allocated resources.
<h3 class=fn><a href="tqvaluelist.html">TQValueList</a><TQHostAddress> <a name="addresses"></a>TQDns::addresses () const
</h3>
Returns a list of the addresses for this name if this TQDns object
has a <a href="#recordType">recordType</a>() of <a href="#RecordType-enum">TQDns::A</a> or <a href="#RecordType-enum">TQDns::Aaaa</a> and the answer
is available; otherwise returns an empty list.
<p> As a special case, if <a href="#label">label</a>() is a valid numeric IP address, this
function returns that address.
<p> Note that if you want to iterate over the list, you should iterate
over a copy, e.g.
<pre>
<a href="tqvaluelist.html">TQValueList</a><TQHostAddress> list = myDns.addresses();
TQValueList<TQHostAddress>::Iterator it = list.<a href="tqvaluelist.html#begin">begin</a>();
while( it != list.<a href="tqvaluelist.html#end">end</a>() ) {
myProcessing( *it );
++it;
}
</pre>
<p>
<h3 class=fn><a href="tqstring.html">TQString</a> <a name="canonicalName"></a>TQDns::canonicalName () const
</h3>
Returns the canonical name for this DNS node. (This works
regardless of what <a href="#recordType">recordType</a>() is set to.)
<p> If the canonical name isn't known, this function returns a null
string.
<p> The canonical name of a DNS node is its full name, or the full
name of the target of its CNAME. For example, if l.trolltech.com
is a CNAME to lillian.troll.no, and the search path for TQDns is
"trolltech.com", then the canonical name for all of "lillian",
"l", "lillian.troll.no." and "l.trolltech.com" is
"lillian.troll.no.".
<h3 class=fn><a href="tqstringlist.html">TQStringList</a> <a name="hostNames"></a>TQDns::hostNames () const
</h3>
Returns a list of host names if the record type is <a href="#RecordType-enum">Ptr</a>.
<p> Note that if you want to iterate over the list, you should iterate
over a copy, e.g.
<pre>
<a href="tqstringlist.html">TQStringList</a> list = myDns.hostNames();
TQStringList::Iterator it = list.<a href="tqvaluelist.html#begin">begin</a>();
while( it != list.<a href="tqvaluelist.html#end">end</a>() ) {
myProcessing( *it );
++it;
}
</pre>
<p>
<h3 class=fn>bool <a name="isWorking"></a>TQDns::isWorking () const
</h3>
Returns TRUE if TQDns is doing a lookup for this object (i.e. if it
does not already have the necessary information); otherwise
returns FALSE.
<p> TQDns emits the <a href="#resultsReady">resultsReady</a>() signal when the status changes to FALSE.
<p>Example: <a href="mail-example.html#x705">network/mail/smtp.cpp</a>.
<h3 class=fn><a href="tqstring.html">TQString</a> <a name="label"></a>TQDns::label () const
</h3>
<p> Returns the domain name for which this object returns information.
<p> <p>See also <a href="#setLabel">setLabel</a>().
<h3 class=fn><a href="tqvaluelist.html">TQValueList</a><MailServer> <a name="mailServers"></a>TQDns::mailServers () const
</h3>
Returns a list of mail servers if the record type is <a href="#RecordType-enum">Mx</a>. The
class <tt>TQDns::MailServer</tt> contains the following public variables:
<ul>
<li> <a href="tqstring.html">TQString</a> TQDns::MailServer::name
<li> TQ_UINT16 TQDns::MailServer::priority
</ul>
<p> Note that if you want to iterate over the list, you should iterate
over a copy, e.g.
<pre>
<a href="tqvaluelist.html">TQValueList</a><TQDns::MailServer> list = myDns.mailServers();
TQValueList<TQDns::MailServer>::Iterator it = list.<a href="tqvaluelist.html#begin">begin</a>();
while( it != list.<a href="tqvaluelist.html#end">end</a>() ) {
myProcessing( *it );
++it;
}
</pre>
<p>
<p>Example: <a href="mail-example.html#x706">network/mail/smtp.cpp</a>.
<h3 class=fn><a href="tqstringlist.html">TQStringList</a> <a name="qualifiedNames"></a>TQDns::qualifiedNames () const
</h3>
<p> Returns a list of the fully qualified names <a href="#label">label</a>() maps to.
<p> Note that if you want to iterate over the list, you should iterate
over a copy, e.g.
<pre>
<a href="tqstringlist.html">TQStringList</a> list = myDns.qualifiedNames();
TQStringList::Iterator it = list.<a href="tqvaluelist.html#begin">begin</a>();
while( it != list.<a href="tqvaluelist.html#end">end</a>() ) {
myProcessing( *it );
++it;
}
</pre>
<p>
<h3 class=fn><a href="tqdns.html#RecordType-enum">RecordType</a> <a name="recordType"></a>TQDns::recordType () const
</h3>
<p> Returns the record type of this DNS query object.
<p> <p>See also <a href="#setRecordType">setRecordType</a>() and <a href="#RecordType-enum">RecordType</a>.
<h3 class=fn>void <a name="resultsReady"></a>TQDns::resultsReady ()<tt> [signal]</tt>
</h3>
<p> This signal is emitted when results are available for one of the
<a href="#qualifiedNames">qualifiedNames</a>().
<p>Example: <a href="mail-example.html#x707">network/mail/smtp.cpp</a>.
<h3 class=fn><a href="tqvaluelist.html">TQValueList</a><Server> <a name="servers"></a>TQDns::servers () const
</h3>
Returns a list of servers if the record type is <a href="#RecordType-enum">Srv</a>. The class
<tt>TQDns::Server</tt> contains the following public variables:
<ul>
<li> <a href="tqstring.html">TQString</a> TQDns::Server::name
<li> TQ_UINT16 TQDns::Server::priority
<li> TQ_UINT16 TQDns::Server::weight
<li> TQ_UINT16 TQDns::Server::port
</ul>
<p> Note that if you want to iterate over the list, you should iterate
over a copy, e.g.
<pre>
<a href="tqvaluelist.html">TQValueList</a><TQDns::Server> list = myDns.servers();
TQValueList<TQDns::Server>::Iterator it = list.<a href="tqvaluelist.html#begin">begin</a>();
while( it != list.<a href="tqvaluelist.html#end">end</a>() ) {
myProcessing( *it );
++it;
}
</pre>
<h3 class=fn>void <a name="setLabel"></a>TQDns::setLabel ( const <a href="tqstring.html">TQString</a> & label )<tt> [virtual]</tt>
</h3>
Sets this DNS query object to query for information about <em>label</em>.
<p> This does not change the <a href="#recordType">recordType</a>(), but its <a href="#isWorking">isWorking</a>() status
will probably change as a result.
<p> The DNS lookup is started the next time the application enters the
event loop. When the result is found the signal <a href="#resultsReady">resultsReady</a>() is
emitted.
<h3 class=fn>void <a name="setLabel-2"></a>TQDns::setLabel ( const <a href="tqhostaddress.html">TQHostAddress</a> & address )<tt> [virtual]</tt>
</h3>
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Sets this DNS query object to query for information about the host
address <em>address</em>. The label is set to the IN-ADDR.ARPA domain
name. This is useful in combination with the <a href="#RecordType-enum">Ptr</a> record type
(e.g. if you want to look up a hostname for a given address).
<h3 class=fn>void <a name="setRecordType"></a>TQDns::setRecordType ( <a href="tqdns.html#RecordType-enum">RecordType</a> rr = A )<tt> [virtual]</tt>
</h3>
Sets this object to query for record type <em>rr</em> records.
<p> The DNS lookup is started the next time the application enters the
event loop. When the result is found the signal <a href="#resultsReady">resultsReady</a>() is
emitted.
<p> <p>See also <a href="#RecordType-enum">RecordType</a>.
<h3 class=fn><a href="tqstringlist.html">TQStringList</a> <a name="texts"></a>TQDns::texts () const
</h3>
Returns a list of texts if the record type is <a href="#RecordType-enum">Txt</a>.
<p> Note that if you want to iterate over the list, you should iterate
over a copy, e.g.
<pre>
<a href="tqstringlist.html">TQStringList</a> list = myDns.texts();
TQStringList::Iterator it = list.<a href="tqvaluelist.html#begin">begin</a>();
while( it != list.<a href="tqvaluelist.html#end">end</a>() ) {
myProcessing( *it );
++it;
}
</pre>
<!-- 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>
|
