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Eneboo - Documentación para desarrolladores
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Eneboo - Documentación para desarrolladores
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The QDns class provides asynchronous DNS lookups.networkBoth 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. Más...
#include <qdns.h>
The QDns class provides asynchronous DNS lookups.
network
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.
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.
The class is not straightforward to use (although it is much simpler than the native APIs); QSocket 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.)
The API comprises a constructor, functions to set the DNS node (the domain in DNS terminology) and record type (setLabel() and setRecordType()), the corresponding get functions, an isWorking() function to determine whether QDns is working or reading, a resultsReady() signal and query functions for the result.
There is one query function for each RecordType, namely addresses(), mailServers(), servers(), hostNames() and texts(). There are also two generic query functions: canonicalName() returns the name you'll presumably end up using (the exact meaning of this depends on the record type) and qualifiedNames() returns a list of the fully qualified names label() maps to.
| enum QDns::RecordType |
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:
None No information. This exists only so that QDns can have a default.
A IPv4 addresses. By far the most common type.
Aaaa IPv6 addresses. So far mostly unused.
Mx Mail eXchanger names. Used for mail delivery.
Srv SeRVer names. Generic record type for finding servers. So far mostly unused.
Cname Canonical names. Maps from nicknames to the true name (the canonical name) for a host.
Ptr name PoinTeRs. Maps from IPv4 or IPv6 addresses to hostnames.
Txt arbitrary TeXT for domains.
We expect that some support for the RFC-2535 extensions will be added in future versions.
| enum QDns::RecordType |
| QDns::QDns | ( | ) |
Constructs a DNS query object with invalid settings for both the label and the search type.
| QDns::QDns | ( | const QString & | label, |
| RecordType | rr = A |
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| ) |
Constructs a DNS query object that will return record type rr information about label.
The DNS lookup is started the next time the application enters the event loop. When the result is found the signal resultsReady() is emitted.
rr defaults to A, IPv4 addresses.
| QDns::QDns | ( | const QHostAddress & | address, |
| RecordType | rr = Ptr |
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| ) |
Constructs a DNS query object that will return record type rr information about host address address. The label is set to the IN-ADDR.ARPA domain name. This is useful in combination with the Ptr record type (e.g. if you want to look up a hostname for a given address).
The DNS lookup is started the next time the application enters the event loop. When the result is found the signal resultsReady() is emitted.
rr defaults to Ptr, that maps addresses to hostnames.
| QDns::~QDns | ( | ) | [virtual] |
Destroys the DNS query object and frees its allocated resources.
| QDns::QDns | ( | ) |
| QDns::QDns | ( | const QString & | label, |
| RecordType | rr = A |
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| ) |
| QDns::QDns | ( | const QHostAddress & | address, |
| RecordType | rr = Ptr |
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| ) |
| virtual QDns::~QDns | ( | ) | [virtual] |
| QValueList< QHostAddress > QDns::addresses | ( | ) | const |
Returns a list of the addresses for this name if this QDns object has a recordType() of QDns::A or QDns::Aaaa and the answer is available; otherwise returns an empty list.
As a special case, if label() is a valid numeric IP address, this function returns that address.
Note that if you want to iterate over the list, you should iterate over a copy, e.g.
QValueList<QHostAddress> list = myDns.addresses(); QValueList<QHostAddress>::Iterator it = list.begin(); while( it != list.end() ) { myProcessing( *it ); ++it; }
| QValueList<QHostAddress> QDns::addresses | ( | ) | const |
| QString QDns::canonicalName | ( | ) | const |
Returns the canonical name for this DNS node. (This works regardless of what recordType() is set to.)
If the canonical name isn't known, this function returns a null string.
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.".
| QString QDns::canonicalName | ( | ) | const |
| QStringList QDns::hostNames | ( | ) | const |
Returns a list of host names if the record type is Ptr.
Note that if you want to iterate over the list, you should iterate over a copy, e.g.
QStringList list = myDns.hostNames(); QStringList::Iterator it = list.begin(); while( it != list.end() ) { myProcessing( *it ); ++it; }
| QStringList QDns::hostNames | ( | ) | const |
| bool QDns::isWorking | ( | ) | const |
| bool QDns::isWorking | ( | ) | const |
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.
QDns emits the resultsReady() signal when the status changes to FALSE.
| QString QDns::label | ( | ) | const [inline] |
| QString QDns::label | ( | ) | const [inline] |
Returns the domain name for which this object returns information.
| QValueList< QDns::MailServer > QDns::mailServers | ( | ) | const |
Returns a list of mail servers if the record type is Mx. The class QDns::MailServer contains the following public variables: QString QDns::MailServer::name Q_UINT16 QDns::MailServer::priority
Note that if you want to iterate over the list, you should iterate over a copy, e.g.
QValueList<QDns::MailServer> list = myDns.mailServers(); QValueList<QDns::MailServer>::Iterator it = list.begin(); while( it != list.end() ) { myProcessing( *it ); ++it; }
| QValueList<MailServer> QDns::mailServers | ( | ) | const |
| QStringList QDns::qualifiedNames | ( | ) | const [inline] |
Returns a list of the fully qualified names label() maps to.
Note that if you want to iterate over the list, you should iterate over a copy, e.g.
QStringList list = myDns.qualifiedNames(); QStringList::Iterator it = list.begin(); while( it != list.end() ) { myProcessing( *it ); ++it; }
| QStringList QDns::qualifiedNames | ( | ) | const [inline] |
| QDns::RecordType QDns::recordType | ( | ) | const [inline] |
Returns the record type of this DNS query object.
| RecordType QDns::recordType | ( | ) | const [inline] |
| void QDns::resultsReady | ( | ) | [signal] |
| void QDns::resultsReady | ( | ) | [signal] |
This signal is emitted when results are available for one of the qualifiedNames().
| QValueList<Server> QDns::servers | ( | ) | const |
| QValueList< QDns::Server > QDns::servers | ( | ) | const |
Returns a list of servers if the record type is Srv. The class QDns::Server contains the following public variables: QString QDns::Server::name Q_UINT16 QDns::Server::priority Q_UINT16 QDns::Server::weight Q_UINT16 QDns::Server::port
Note that if you want to iterate over the list, you should iterate over a copy, e.g.
QValueList<QDns::Server> list = myDns.servers(); QValueList<QDns::Server>::Iterator it = list.begin(); while( it != list.end() ) { myProcessing( *it ); ++it; }
| void QDns::setLabel | ( | const QHostAddress & | address | ) | [virtual] |
Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Sets this DNS query object to query for information about the host address address. The label is set to the IN-ADDR.ARPA domain name. This is useful in combination with the Ptr record type (e.g. if you want to look up a hostname for a given address).
| void QDns::setLabel | ( | const QString & | label | ) | [virtual] |
Sets this DNS query object to query for information about label.
This does not change the recordType(), but its isWorking() status will probably change as a result.
The DNS lookup is started the next time the application enters the event loop. When the result is found the signal resultsReady() is emitted.
| virtual void QDns::setLabel | ( | const QString & | label | ) | [virtual] |
| virtual void QDns::setLabel | ( | const QHostAddress & | address | ) | [virtual] |
| virtual void QDns::setRecordType | ( | RecordType | rr = A | ) | [virtual] |
| void QDns::setRecordType | ( | RecordType | rr = A | ) | [virtual] |
Sets this object to query for record type rr records.
The DNS lookup is started the next time the application enters the event loop. When the result is found the signal resultsReady() is emitted.
| QStringList QDns::texts | ( | ) | const |
Returns a list of texts if the record type is Txt.
Note that if you want to iterate over the list, you should iterate over a copy, e.g.
QStringList list = myDns.texts(); QStringList::Iterator it = list.begin(); while( it != list.end() ) { myProcessing( *it ); ++it; }
| QStringList QDns::texts | ( | ) | const |
QDnsAnswer [friend] |
QDnsManager [friend] |
1.7.4
