/usr/share/qt3/doc/html/qdns.html is in qt3-doc 3:3.3.8-b-8ubuntu3.
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 | <!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/qdns.cpp:1597 -->
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>QDns 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>QDns Class Reference<br><small>[<a href="network.html">network module</a>]</small></h1>
<p>The QDns class provides asynchronous DNS lookups.
<a href="#details">More...</a>
<p><tt>#include <<a href="qdns-h.html">qdns.h</a>></tt>
<p>Inherits <a href="qobject.html">QObject</a>.
<p><a href="qdns-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="#QDns"><b>QDns</b></a> ()</li>
<li class=fn><a href="#QDns-2"><b>QDns</b></a> ( const QString & label, RecordType rr = A )</li>
<li class=fn><a href="#QDns-3"><b>QDns</b></a> ( const QHostAddress & address, RecordType rr = Ptr )</li>
<li class=fn>virtual <a href="#~QDns"><b>~QDns</b></a> ()</li>
<li class=fn>virtual void <a href="#setLabel"><b>setLabel</b></a> ( const QString & label )</li>
<li class=fn>virtual void <a href="#setLabel-2"><b>setLabel</b></a> ( const QHostAddress & address )</li>
<li class=fn>QString <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>QValueList<QHostAddress> <a href="#addresses"><b>addresses</b></a> () const</li>
<li class=fn>QValueList<MailServer> <a href="#mailServers"><b>mailServers</b></a> () const</li>
<li class=fn>QValueList<Server> <a href="#servers"><b>servers</b></a> () const</li>
<li class=fn>QStringList <a href="#hostNames"><b>hostNames</b></a> () const</li>
<li class=fn>QStringList <a href="#texts"><b>texts</b></a> () const</li>
<li class=fn>QString <a href="#canonicalName"><b>canonicalName</b></a> () const</li>
<li class=fn>QStringList <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 QDns 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> QDns 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="qsocket.html">QSocket</a> provides much easier to use
TCP connection facilities. The aim of QDns 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 QDns 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="qsocket.html">QSocket</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>QDns::RecordType</h3>
<p> This enum type defines the record types QDns 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>QDns::None</tt> - No information. This exists only so that QDns can
have a default.
<li><tt>QDns::A</tt> - IPv4 addresses. By far the most common type.
<li><tt>QDns::Aaaa</tt> - IPv6 addresses. So far mostly unused.
<li><tt>QDns::Mx</tt> - Mail eXchanger names. Used for mail delivery.
<li><tt>QDns::Srv</tt> - SeRVer names. Generic record type for finding
servers. So far mostly unused.
<li><tt>QDns::Cname</tt> - Canonical names. Maps from nicknames to the true
name (the canonical name) for a host.
<li><tt>QDns::Ptr</tt> - name PoinTeRs. Maps from IPv4 or IPv6 addresses to hostnames.
<li><tt>QDns::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="QDns"></a>QDns::QDns ()
</h3>
Constructs a DNS query object with invalid settings for both the
label and the search type.
<h3 class=fn><a name="QDns-2"></a>QDns::QDns ( const <a href="qstring.html">QString</a> & label, <a href="qdns.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="QDns-3"></a>QDns::QDns ( const <a href="qhostaddress.html">QHostAddress</a> & address, <a href="qdns.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="~QDns"></a>QDns::~QDns ()<tt> [virtual]</tt>
</h3>
Destroys the DNS query object and frees its allocated resources.
<h3 class=fn><a href="qvaluelist.html">QValueList</a><QHostAddress> <a name="addresses"></a>QDns::addresses () const
</h3>
Returns a list of the addresses for this name if this QDns object
has a <a href="#recordType">recordType</a>() of <a href="#RecordType-enum">QDns::A</a> or <a href="#RecordType-enum">QDns::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="qvaluelist.html">QValueList</a><QHostAddress> list = myDns.addresses();
QValueList<QHostAddress>::Iterator it = list.<a href="qvaluelist.html#begin">begin</a>();
while( it != list.<a href="qvaluelist.html#end">end</a>() ) {
myProcessing( *it );
++it;
}
</pre>
<p>
<h3 class=fn><a href="qstring.html">QString</a> <a name="canonicalName"></a>QDns::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 QDns 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="qstringlist.html">QStringList</a> <a name="hostNames"></a>QDns::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="qstringlist.html">QStringList</a> list = myDns.hostNames();
QStringList::Iterator it = list.<a href="qvaluelist.html#begin">begin</a>();
while( it != list.<a href="qvaluelist.html#end">end</a>() ) {
myProcessing( *it );
++it;
}
</pre>
<p>
<h3 class=fn>bool <a name="isWorking"></a>QDns::isWorking () const
</h3>
Returns TRUE if QDns is doing a lookup for this object (i.e. if it
does not already have the necessary information); otherwise
returns FALSE.
<p> QDns 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="qstring.html">QString</a> <a name="label"></a>QDns::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="qvaluelist.html">QValueList</a><MailServer> <a name="mailServers"></a>QDns::mailServers () const
</h3>
Returns a list of mail servers if the record type is <a href="#RecordType-enum">Mx</a>. The
class <tt>QDns::MailServer</tt> contains the following public variables:
<ul>
<li> <a href="qstring.html">QString</a> QDns::MailServer::name
<li> Q_UINT16 QDns::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="qvaluelist.html">QValueList</a><QDns::MailServer> list = myDns.mailServers();
QValueList<QDns::MailServer>::Iterator it = list.<a href="qvaluelist.html#begin">begin</a>();
while( it != list.<a href="qvaluelist.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="qstringlist.html">QStringList</a> <a name="qualifiedNames"></a>QDns::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="qstringlist.html">QStringList</a> list = myDns.qualifiedNames();
QStringList::Iterator it = list.<a href="qvaluelist.html#begin">begin</a>();
while( it != list.<a href="qvaluelist.html#end">end</a>() ) {
myProcessing( *it );
++it;
}
</pre>
<p>
<h3 class=fn><a href="qdns.html#RecordType-enum">RecordType</a> <a name="recordType"></a>QDns::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>QDns::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="qvaluelist.html">QValueList</a><Server> <a name="servers"></a>QDns::servers () const
</h3>
Returns a list of servers if the record type is <a href="#RecordType-enum">Srv</a>. The class
<tt>QDns::Server</tt> contains the following public variables:
<ul>
<li> <a href="qstring.html">QString</a> QDns::Server::name
<li> Q_UINT16 QDns::Server::priority
<li> Q_UINT16 QDns::Server::weight
<li> Q_UINT16 QDns::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="qvaluelist.html">QValueList</a><QDns::Server> list = myDns.servers();
QValueList<QDns::Server>::Iterator it = list.<a href="qvaluelist.html#begin">begin</a>();
while( it != list.<a href="qvaluelist.html#end">end</a>() ) {
myProcessing( *it );
++it;
}
</pre>
<h3 class=fn>void <a name="setLabel"></a>QDns::setLabel ( const <a href="qstring.html">QString</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>QDns::setLabel ( const <a href="qhostaddress.html">QHostAddress</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>QDns::setRecordType ( <a href="qdns.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="qstringlist.html">QStringList</a> <a name="texts"></a>QDns::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="qstringlist.html">QStringList</a> list = myDns.texts();
QStringList::Iterator it = list.<a href="qvaluelist.html#begin">begin</a>();
while( it != list.<a href="qvaluelist.html#end">end</a>() ) {
myProcessing( *it );
++it;
}
</pre>
<!-- eof -->
<hr><p>
This file is part of the <a href="index.html">Qt 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>Qt 3.3.8</div>
</table></div></address></body>
</html>
|