Qore TelnetClient Module Reference  1.0
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TelnetClient::TelnetClient Class Reference

The TelnetClient class allows communication with a telnet server; it can be used directly or subclassed with overridden methods to customize its behavior. More...

Public Member Functions

 constructor (string host, softint port, *code log, *code dbgLog)
 creates the TelnetClient object
 
 constructor (string connect, *code log, *code dbglog)
 creates the TelnetClient object
 
 destructor ()
 disconnects from the server if connected and deletes the object
 
 connect (timeout timeout=DefaultConnTimeout)
 connects to the Telnet server
 
bool isConnected ()
 returns True if the client is connected to the server
 
 setUser (*string user)
 sets or clears (in case passed with no value) the username parameter for logging in to the telnet server
 
*string getUser ()
 returns the current value of the username parameter
 
 disconnect ()
 disconnects from the Telnet server
 
 sendData (softlist arr)
 sends data to the server
 
 sendTextData (string str)
 sends literal string data to the server; the text dat is converted to the socket's encoding if necessary
 
*string getAvailableData (timeout t=DefaultTimeout)
 returns all data available as a string (which could be an empty string if no data is available in the timeout period) or NOTHING if the connection was closed by the remote end
 
bool hasFeature (int fc)
 returns True if the server has confirmed with a DO command that it supports the given feature
 
 windowSizeUpdated ()
 this method should be called externally when the window size has changed
 

Private Member Functions

 log (string msg)
 logs the message to the log closure set with the constructor (if any)
 
 logDbg (string msg)
 logs the message to the debug log closure set with the constructor (if any)
 
*string getDisplay ()
 this method provides the value that will be given as the DISPLAY value in protocol negotiation
 
*string getTerminalType ()
 this method provides the value that will be given as the terminal type in protocol negotiation
 
hash getEnvironment ()
 this method provides the value that will be given as the user's environment in protocol negotiation
 
int getTerminalSpeed ()
 this method provides the value that will be given as the terminal speed in protocol negotiation
 
hash getWindowSize ()
 this method provides the value that will be given as the terminal window size in protocol negotiation
 

Detailed Description

The TelnetClient class allows communication with a telnet server; it can be used directly or subclassed with overridden methods to customize its behavior.

This class uses a Mutex lock in each TelnetClient object to ensure thread serialization to the underlying socket and its internal configuration, so it is safe to access in a multithreaded context.

Member Function Documentation

TelnetClient::TelnetClient::connect ( timeout  timeout = DefaultConnTimeout)

connects to the Telnet server

If the object is already connected, it is disconnected and a new connection attempt is made.

Note
This method is subject to thread serialization.
TelnetClient::TelnetClient::constructor ( string  host,
softint  port,
*code  log,
*code  dbgLog 
)

creates the TelnetClient object

Parameters
hostthe hostname of the telnet server (use [hostname] to explicitly specify an ipv6 connection)
portthe port number of the telnet server
loga closure or call reference for log messages; a single string argument will be passed to this code for logging
dbgLoga closure for debugging/technical log messages; a single string argument will be passed to this code for logging
TelnetClient::TelnetClient::constructor ( string  connect,
*code  log,
*code  dbglog 
)

creates the TelnetClient object

Parameters
connectthe hostname of the Telnet server or a hostname:port specification (use [hostname] or [address] for ipv6 connections)
loga closure or call reference for log messages; a single string argument will be passed to this code for logging
dbgloga closure for debugging/technical log messages; a single string argument will be passed to this code for logging
TelnetClient::TelnetClient::disconnect ( )

disconnects from the Telnet server

Note
This method is subject to thread serialization.
*string TelnetClient::TelnetClient::getAvailableData ( timeout  t = DefaultTimeout)

returns all data available as a string (which could be an empty string if no data is available in the timeout period) or NOTHING if the connection was closed by the remote end

NOTHING is only returned if the remote end closed the connection

Note
  • This method could throw any exception that Socket::recvu1() could throw except SOCKET-CLOSED (in which case the exception is caught and NOTHING is returned)
  • This method is subject to thread serialization
*string TelnetClient::TelnetClient::getDisplay ( )
private

this method provides the value that will be given as the DISPLAY value in protocol negotiation

override this method in a subclass to provide a different value

hash TelnetClient::TelnetClient::getEnvironment ( )
private

this method provides the value that will be given as the user's environment in protocol negotiation

override this method in a subclass to provide a different value

int TelnetClient::TelnetClient::getTerminalSpeed ( )
private

this method provides the value that will be given as the terminal speed in protocol negotiation

override this method in a subclass to provide a different value

*string TelnetClient::TelnetClient::getTerminalType ( )
private

this method provides the value that will be given as the terminal type in protocol negotiation

override this method in a subclass to provide a different value

hash TelnetClient::TelnetClient::getWindowSize ( )
private

this method provides the value that will be given as the terminal window size in protocol negotiation

The default implementation of this method is to return the actual terminal size by calling TermIOS::getWindowSize(). Override this method in a subclass to provide a different value.

Returns
a hash with the following keys:
  • rows: the number of rows in the display
  • columns: the number of columns in the display
bool TelnetClient::TelnetClient::hasFeature ( int  fc)

returns True if the server has confirmed with a DO command that it supports the given feature

Parameters
fcThe feature code to check; see Telnet Command Option Codes for possible values; supported features are:
TelnetClient::TelnetClient::sendData ( softlist  arr)

sends data to the server

Parameters
arra single element or a list of elements to send to the server; elements can be as follows:
  • string: currently sent verbatim to the server, in particular no encoding conversions are performed on this string (possibly these should be scanned for IAC characters which should be duplicated)
  • integer: treated as a single-byte value; if the value is IAC (ie 255 or 0xff) then it is sent twice
  • binary: sent verbatim to the server
Exceptions
SEND-ERRORthis exception is thrown if an invalid data type is passed to this method
NOT-CONNECTED-EXCEPTIONif the socket is not already connected then this exception is thrown
Note
  • This method could also throw any exception that Socket::sendBinary2() or Socket::sendi1() could throw
  • This method is subject to thread serialization
TelnetClient::TelnetClient::sendTextData ( string  str)

sends literal string data to the server; the text dat is converted to the socket's encoding if necessary

Parameters
strcurrently sent verbatim to the server; no encoding conversions are performed on this string (possibly these should be scanned for IAC characters which should be duplicated)
Exceptions
NOT-CONNECTED-EXCEPTIONif the socket is not already connected then this exception is thrown
Note
  • This method could also throw any exception that Socket::sendBinary2() could throw
  • This method is subject to thread serialization
TelnetClient::TelnetClient::setUser ( *string  user)

sets or clears (in case passed with no value) the username parameter for logging in to the telnet server

Note
This method is subject to thread serialization.
TelnetClient::TelnetClient::windowSizeUpdated ( )

this method should be called externally when the window size has changed

See Also
getWindowSize()