This is an example of how to program a simple subscriber application. To compile this example on a GNU/Linux system or on other Unix-like systems, assuming Siena has been installed in $prefix, execute:
c++ subscriber.cc -o subscriber -I$prefix/include -L$prefix/lib -lsiena
On some platforms (notably Solaris), you will have to link additional libraris (e.g., -lsocket -lnsl).
To compile this example on a win32 system, using Visual C++, assuming Siena has been installed in %prefix%, execute:
cl -I%prefix% -GX -c subscriber.cc link -out:subscriber subscriber.obj %prefix%\siena.lib wsock32.lib
// -*- C++ -*- // // This file is part of Siena, a wide-area event notification system. // See http://www.cs.colorado.edu/serl/siena/ // // Author: Antonio Carzaniga <carzanig@cs.colorado.edu> // See the file AUTHORS for full details. // // Copyright (C) 1998-2001 University of Colorado // // This program is free software; you can redistribute it and/or // modify it under the terms of the GNU General Public License // as published by the Free Software Foundation; either version 2 // of the License, or (at your option) any later version. // // This program is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with this program; if not, write to the Free Software // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, // USA, or send email to serl@cs.colorado.edu. // // $Id: subscriber.cc,v 1.2 2001/06/26 22:03:03 carzanig Exp $ // #include <string.h> #include <stdlib.h> #include <iostream> #include <exception> // include Siena headers #include <siena/Siena.h> #include <siena/ThinClient.h> static void print_usage(const char * progname) { cerr << "usage: " << progname << " [-udp] [-port <num>] [-host <host>] <uri-master>" << endl; } int main (int argc, char *argv[]) { bool udp = false; unsigned short port = 1969; const char * master = NULL; const char * thishost = NULL; try { int i; for(i=1; i < argc; ++i) { // parse cmd-line params if(strcmp(argv[i], "-udp")==0) { udp = true; } else if (strcmp(argv[i], "-port")==0) { if (++i < argc) { port = atoi(argv[i]); } else { print_usage(argv[0]); return 1; } } else if (strcmp(argv[i], "-host")==0) { if (++i < argc) { thishost = argv[i]; } else { print_usage(argv[0]); return 1; } } else { master = argv[i]; } } if (master == NULL) { print_usage(argv[0]); return 1; } ThinClient siena(master); // create interface to Receiver * r; // given master server if (udp) { r = new UDPReceiver(port, thishost);// create receiver for } else { // this interface r = new TCPReceiver(port, thishost); } siena.set_receiver(r); // set receiver Filter f; // create subscription filter f.add_constraint("stock", SX_eq, "XYZ"); f.add_constraint("price", SX_lt, (long)100); siena.subscribe(f); // subscribe Notification * n; for (i = 1; i < 20; ++i) { // read incoming notifications n = siena.get_notification(); if (n != NULL) { cout << "stock=" << (*n)["stock"].string_value() << " price=" << (*n)["price"].int_value() << endl; delete(n); } } siena.unsubscribe(); // unsubscribe and shutdown siena.shutdown(); // interface delete(r); } catch (exception &ex) { cout << "error: " << ex.what() << endl; } return 0; }