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diff --git a/docs/tutorials/008/page03.html b/docs/tutorials/008/page03.html deleted file mode 100644 index b1faf3b7287..00000000000 --- a/docs/tutorials/008/page03.html +++ /dev/null @@ -1,187 +0,0 @@ -<HTML> -<HEAD> - <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> - <META NAME="GENERATOR" CONTENT="Mozilla/4.05 [en] (WinNT; I) [Netscape]"> - <META NAME="Author" CONTENT="James CE Johnson"> - <TITLE>ACE Tutorial 008</TITLE> -</HEAD> -<BODY TEXT="#000000" BGCOLOR="#FFFFFF" LINK="#000FFF" VLINK="#FF0F0F"> - -<CENTER><B><FONT SIZE=+2>ACE Tutorial 008</FONT></B></CENTER> - -<CENTER><B><FONT SIZE=+2>Sending and receiving datagrams</FONT></B></CENTER> - - -<P> -<HR WIDTH="100%"> - -<P>In <A HREF="directed_client.cpp">directed_client.cpp</A> we create a -client that knows how to send a datagram to a server on a known host. -This is a good thing if you know where the server lives and want to have -a conversation. The Unix <I>talk</I> utilitiy, for instance, -could be written this way. - -<P> -<HR WIDTH="100%"> - -<P><TT>#include "ace/SOCK_Dgram.h"</TT> -<BR><TT>#include "ace/INET_Addr.h"</TT> - -<P><TT>/*</TT> -<BR><TT> Once again, we use the default server port. -In a "real" system,</TT> -<BR><TT> the server's port (or ports) would be published in -some way so</TT> -<BR><TT> that clients would know where to "look". We -could even add entries</TT> -<BR><TT> to the operating system's services file and use a -service name</TT> -<BR><TT> instead of a number. We'll come back to that -in some other tutorial</TT> -<BR><TT> though. For now, let's stay simple.</TT> -<BR><TT> */</TT> -<BR><TT>static const u_short PORT = ACE_DEFAULT_SERVER_PORT;</TT> - -<P><TT>/*</TT> -<BR><TT> Our goal here is to develop a client that can send -a datagram to</TT> -<BR><TT> a server running on a known host. We'll use -a command-line argument</TT> -<BR><TT> to specify the hostname instead of hard-coding it.</TT> -<BR><TT> */</TT> -<BR><TT>int main(int argc,char *argv[] )</TT> -<BR><TT>{</TT> -<BR><TT> /*</TT> -<BR><TT> All -datagrams have to have a point of origin. Since we intend to</TT> -<BR><TT> transmit -instead of receive, we initialize an address with zero</TT> -<BR><TT> and -let the OS choose a port for us. We could have chosen our</TT> -<BR><TT> own -value between 1025 and 65535 as long as it isn't already in use.</TT> -<BR><TT> */</TT> -<BR><TT> ACE_INET_Addr -local((u_short)0);</TT> - -<P><TT> /*</TT> -<BR><TT> And -here is our datagram object.</TT> -<BR><TT> */</TT> -<BR><TT> ACE_SOCK_Dgram dgram;</TT> -<BR><TT> </TT> -<BR><TT> /*</TT> -<BR><TT> Notice -that this looks a lot like the server application. There's</TT> -<BR><TT> no -difference in creating server datagrams an client datagrams.</TT> -<BR><TT> You -can even use a zero-constructed address for your server datagram</TT> -<BR><TT> as -long as you tell the client where you're listening (eg -- by writting</TT> -<BR><TT> into -a file or some such).</TT> -<BR><TT> */</TT> -<BR><TT> if( dgram.open(local) -== -1 )</TT> -<BR><TT> {</TT> -<BR><TT> -ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "datagram open"),-1);</TT> -<BR><TT> }</TT> - -<P><TT> /*</TT> -<BR><TT> Yep. -We've seen this before too...</TT> -<BR><TT> */</TT> -<BR><TT> char buf[512];</TT> - -<P><TT> /*</TT> -<BR><TT> Ok, -now we're doing something different.</TT> -<BR><TT> */</TT> -<BR><TT> sprintf(buf, "Hello -World!");</TT> - -<P><TT> /*</TT> -<BR><TT> Just -like sending a telegram, we have to address our datagram.</TT> -<BR><TT> Here, -we create an address object at the desired port on the</TT> -<BR><TT> chosen -host. To keep us from crashing, we'll provide a default</TT> -<BR><TT> host -name if we aren't given one.</TT> -<BR><TT> */</TT> -<BR><TT> ACE_INET_Addr -remote(PORT, argc > 1 ? argv[1] : "localhost" );</TT> - -<P><TT> ACE_DEBUG ((LM_DEBUG, -"(%P|%t) Sending (%s) to the server.\n",buf));</TT> -<BR><TT> /*</TT> -<BR><TT> -Now we send our buffer of stuff to the remote address. This is</TT> -<BR><TT> -just exactly what the server did after receiving a client message.</TT> -<BR><TT> -Datagrams are rather orthogonal that way: they don't generally make</TT> -<BR><TT> -much of a fuss about being either client or server.</TT> -<BR><TT> */</TT> -<BR><TT> if( dgram.send(buf,strlen(buf)+1,remote) -== -1 )</TT> -<BR><TT> {</TT> -<BR><TT> -ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "send"),-1);</TT> -<BR><TT> }</TT> - -<P><TT> /*</TT> -<BR><TT> Now -we've turned around and put ourselves into "server mode" by</TT> -<BR><TT> invoking -the recv() method. We now our server is going to send</TT> -<BR><TT> us -something, so we hang out here and wait for it. Because we</TT> -<BR><TT> know -datagrams are unreliable, there is a chance that the server</TT> -<BR><TT> will -respond but we won't hear. You might consider providing a</TT> -<BR><TT> timeout -on the recv() in that case. If recv() fails due to timeout</TT> -<BR><TT> it -will return -1 and you can then resend your query and attempt</TT> -<BR><TT> the -recv() again.</TT> -<BR><TT> */</TT> -<BR><TT> if( dgram.recv(buf,sizeof(buf),remote) -== -1 )</TT> -<BR><TT> {</TT> -<BR><TT> -ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "recv"),-1);</TT> -<BR><TT> }</TT> - -<P><TT> /*</TT> -<BR><TT> Find -out what the server had to say.</TT> -<BR><TT> */</TT> -<BR><TT> ACE_DEBUG ((LM_DEBUG, -"(%P|%t) The server said: %s\n",buf));</TT> - -<P><TT> return(0);</TT> -<BR><TT>}</TT> - -<P> -<HR WIDTH="100%"> - -<P>That's all neat and good but the point of what we're doing here is not -to talk to a server we know about but to discover servers we don't know -about. Now, you could send a directed datagram to every possible -host address on your network but that's not a very nice thing to do. -On the next page, we'll find out the right approach... - -<P> -<HR WIDTH="100%"> -<CENTER>[<A HREF="..">Tutorial Index</A>] [<A HREF="page04.html">Continue -This Tutorial</A>]</CENTER> - -</BODY> -</HTML> |