TCPIP Socket Server Example

[Omron Forums Support]

Here's an example of how to make Power PMAC a TCP/IP socket server (through a background C program) that echoes back whatever strings it receives from clients (this is a synchronous example; threading can be used to handle multiple clients and asynchronous communication):

 

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include    // Global Gp Shared memory pointer
#include "../../Include/pp_proj.h"

#define MAXPENDING 5    /* Max connection requests */
#define BUFFSIZE 32
void Die(char *mess) { perror(mess); exit(1); }

// Prototypes
void HandleClient(int sock);

int main(int argc, char *argv[]) {
{
int serversock, clientsock;
struct sockaddr_in server, client;
InitLibrary();

if (argc != 2) {
 fprintf(stderr, "USAGE: server \n"); // Can pass any port here; 1024 works usually
 exit(1);
}

/* Create the TCP socket */
if ((serversock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
 Die("Failed to create socket");
}
// Construct the server sockaddr_in structure 
memset(&server, 0, sizeof(server));       /* Clear struct */
server.sin_family = AF_INET;                  /* Internet/IP */
server.sin_addr.s_addr = htonl(INADDR_ANY);   /* Incoming addr */
server.sin_port = htons(atoi(argv[1]));       /* server port */

// Bind the server socket 
if (bind(serversock, (struct sockaddr *) &server,
                          sizeof(server)) < 0) {
Die("Failed to bind the server socket");
}
// Listen on the server socket 
if (listen(serversock, MAXPENDING) < 0) {
Die("Failed to listen on server socket");
}

// Run until cancelled 
while (1) {
 unsigned int clientlen = sizeof(client);
 // Wait for client connection 
 if ((clientsock =
      accept(serversock, (struct sockaddr *) &client,
             &clientlen)) < 0) {
   Die("Failed to accept client connection");
 }
 fprintf(stdout, "Client connected: %s\n",
                 inet_ntoa(client.sin_addr));
 HandleClient(clientsock);
}
}

CloseLibrary();	
return 0;
}

// HandleClient operates once the server accepts connection with the client
void HandleClient(int sock) {
char buffer[bUFFSIZE];
int received = -1;
/* Receive message */
if ((received = recv(sock, buffer, BUFFSIZE, 0)) < 0) {
 Die("Failed to receive initial bytes from client");
}
/* Send bytes and check for more incoming data in loop */
while (received > 0) {
 /* Send back received data */
 if (send(sock, buffer, received, 0) != received) {
   Die("Failed to send bytes to client");
 }
 /* Check for more data */
 if ((received = recv(sock, buffer, BUFFSIZE, 0)) < 0) {
   Die("Failed to receive additional bytes from client");
 }
}
close(sock);
}

 

When you run the .out file after compiling this program, pass it the port number to which you want the program to listen.

[piefum]

Here's an example of how to make Power PMAC a TCP/IP socket server (through a background C program) that echoes back whatever strings it receives from clients When you run the .out file after compiling this program, pass it the port number to which you want the program to listen.

 

Hi Charles,

thanks for the great tip.

As you might remember, I tried to do a similar thing, using the ZeroMQ C libraries (see http://forums.deltatau.com/showthread.php?tid=910). At the moment I cannot compile under the IDE (it cannot link the libraries), so I compile it directly inside the PMAC. Is this problem solved in the IDE 2.0?

Unfortunately right now I am delivering a product so I don't have time to setup a new machine to test the IDE2.0.

 

Thanks

gigi

[Omron Forums Support]

There were a few compiler issues that have been fixed in the new (patched) version of the IDE. You may want to consider trying it again within the IDE in the future.

 

Note that there will be a "patch" released that will fix a few things in version 2.0.