input reader stdio commands get url

from twisted.internet import stdio , reactor
from twisted.protocols import basic
from twisted.web import client


class URLGetCommandProtocol( basic.LineReceiver ):

    delimiter = '\n' # unix terminal style newlines. remove this line if using with Telnet


    def connectionMade( self ):
        self.sendLine( "Type 'help' for help." )


    def lineReceived( self , line ):
        if not line: return         # Ignore blank lines

        commandParts = line.split( )
        command = commandParts[ 0 ].lower( )        # first part is the command
        args = commandParts[ 1: ]                   # second parts are the argument(s)

        # Dispatching: to implement a new command add another do_ method.
        try:
            method = getattr( self , 'do_' + command )
        except AttributeError , e:
            self.sendLine( 'Error: no such command.' )
        else:
            try:
                method( *args )         # the method name created by concatenating the do_ with the user provided command
            except Exception , e:
                self.sendLine( 'Error: ' + str( e ) )


    def do_help( self , command = None ):
        """help [command]: List commands, or show help on the given command"""
        if command:
            self.sendLine( getattr( self , 'do_' + command ).__doc__ )
        else:
            commands = [ cmd[ 3: ] for cmd in dir( self ) if cmd.startswith( 'do_' ) ]
            self.sendLine( "Valid commands: " + " ".join( commands ) )


    def do_exit( self ):
        self.sendLine( 'Exiting.' )
        self.transport.loseConnection( )


    def do_get( self, url ):
        """get <url>: download the url"""
        client.getPage( url ).addCallback( self.__checkSuccess ).addErrback( self.__checkFailure )


    def __checkSuccess( self, pageData ):
        self.sendLine( "Success: got %i bytes." % len( pageData ) )


    def __checkFailure( self, failure ):
        self.sendLine( "Failure: " + failure.getErrorMessage( ) )


    def connectionLost( self, reason ):
        reactor.stop( )              # stop the reactor, only because this is meant to be run in Stdio.


if __name__ == "__main__":
    stdio.StandardIO( URLGetCommandProtocol( ) )
    reactor.run( )