FAQ

Frequently Asked Questions

• What is XmlRpc++?

  XmlRpc++ is a C++ implementation of the XML-RPC protocol.
  
  

• What is XML-RPC?

  The XML-RPC protocol was designed to make remote procedure calls (RPCs) easy: it encodes data in a simple XML format and uses HTTP for communication. XML-RPC is intended to be used to implement web services and distributed applications. Check out XML-RPC for Newbies.
  
  

• What other XML-RPC implementations exist?

  XML-RPC implementations
  
  

• Why do we need another XML-RPC implementation (specifically XmlRpc++)?

  XmlRpc++ is designed to make it easy to incorporate XML-RPC client and server support into C++ applications. It is written in portable, extendable C++. No other libraries are required, other than your system's socket libraries. Simple XML parsing and HTTP support are built in. It is easy to build and has a small API. There is no easier way to add remote procedure call support to a C++ application that I know of.
  
  

• Why not use SOAP (or DCE RPC, ONC RPC, CORBA, DCOM, ...)?

  XML-RPC is easy, free, and fast enough for my purposes. Use the tool that best solves your problem.
  
  

• What is an XML-RPC server (client)?

  An XML-RPC server has one or more procedures (or methods) registered, and makes those procedures available to XML-RPC clients over a network (LAN or Internet). An XML-RPC client calls one or more remote procedures provided by an XML-RPC server, and gets a result, much like calling a local procedure (function, method, etc). Arguments and results are converted to an XML format for transfer across the network.
  
  

• How do you use XmlRpc++ as an XML-RPC client?

  Here is an example of a client (taken from the file test/HelloClient.cpp in the XmlRpc++ distribution) that gets a server hostname and port number from the command line and calls a remote procedure named Hello, then prints the result:

  #include "XmlRpc.h"
  #include <iostream>
  
  using namespace XmlRpc;
  
  int main(int argc, char* argv[]) {
    if (argc != 3) {
      std::cerr << "Usage: HelloClient serverHost serverPort\n";
      return -1;
    }
    const char* hostname = argv[1];
    int port = atoi(argv[2]);
  
    // Create a client and connect to the server at hostname:port
    XmlRpcClient c(hostname, port);
  
    XmlRpcValue noArgs, result;
  
    // Call the remote procedure Hello and print the result value
    if (c.execute("Hello", noArgs, result))
      std::cout << result << std::endl;
  }
  							

  
  

• How do you use XmlRpc++ as an XML-RPC server?

  Here is an example of a server (taken from the file test/HelloServer.cpp in the XmlRpc++ distribution) that registers a single remote procedure named Hello and listens on a port for calls to that procedure:

  #include "XmlRpc.h"
  using namespace XmlRpc;
  
  // The server
  XmlRpcServer s;
  
  // The Hello method. No arguments, result is "Hello".
  class Hello : public XmlRpcServerMethod
  {
  public:
    Hello(XmlRpcServer* s) : XmlRpcServerMethod("Hello", s) {}
  
    void execute(XmlRpcValue& params, XmlRpcValue& result)
    {
      result = "Hello";
    }
  
  } hello(&s);    // This constructor registers the method with the server
  
  
  // The port to use
  const int PORT = 8080;
  
  int main(int argc, char* argv[]) {
  
    // Create the server socket on the specified port
    s.bindAndListen(PORT);
  
    // Wait for requests and process indefinitely (Ctrl-C to exit)
    s.work(-1.0);
  
    return 0;
  }