Added comments, added prelim socket work

server/cardnet.cpp

@@ -1,21 +1,29 @@
 /*
-
 Compiler: g++
-Flags: -static-libgcc -static-libstdc++
+Flags: -static-libgcc -static-libstdc++ -lws2_32
+
+TODO:
+Do not send auto reply
+Change card0.txt file based on information given by client
+
 */
 
 #include <iostream>
 #include <string>
 #include "argh.h"
+#include <winsock2.h>
+#include <stdio.h>
+
+#pragma comment(lib,"ws2_32.lib") //Winsock Library
 
 void exampleMessage();
 
 int main (int argc, char* argv[])
 {
-    std::string file, check;
-    int port = 0;
+    std::string file, check; // file = card0.txt ; check = check.txt
+    int port = 0; // port number to listen
 
-    argh::parser cmdl;
+    argh::parser cmdl; // command line parser
     cmdl.parse(argc, argv, argh::parser::PREFER_PARAM_FOR_UNREG_OPTION);
 
     if(cmdl["-h"]) // help
@@ -55,6 +63,180 @@ int main (int argc, char* argv[])
     std::cout << "Check:\t" << check << std::endl;
     std::cout << "Port:\t" << port << std::endl;
 
+    // begin socket work - copy and pasted below (http://www.binarytides.com/code-tcp-socket-server-winsock/)
+    WSADATA wsa;
+    SOCKET master , new_socket , client_socket[30] , s;
+    struct sockaddr_in server, address;
+    int max_clients = 30 , activity, addrlen, i, valread;
+    char *message = "ECHO Daemon v1.0 \r\n";
+     
+    //size of our receive buffer, this is string length.
+    int MAXRECV = 1024;
+    //set of socket descriptors
+    fd_set readfds;
+    //1 extra for null character, string termination
+    char *buffer;
+    buffer =  (char*) malloc((MAXRECV + 1) * sizeof(char));
+ 
+    for(i = 0 ; i < 30;i++)
+    {
+        client_socket[i] = 0;
+    }
+ 
+    printf("\nInitialising Winsock...");
+    if (WSAStartup(MAKEWORD(2,2),&wsa) != 0)
+    {
+        printf("Failed. Error Code : %d",WSAGetLastError());
+        exit(EXIT_FAILURE);
+    }
+     
+    printf("Initialised.\n");
+     
+    //Create a socket
+    if((master = socket(AF_INET , SOCK_STREAM , 0 )) == INVALID_SOCKET)
+    {
+        printf("Could not create socket : %d" , WSAGetLastError());
+        exit(EXIT_FAILURE);
+    }
+ 
+    printf("Socket created.\n");
+     
+    //Prepare the sockaddr_in structure
+    server.sin_family = AF_INET;
+    server.sin_addr.s_addr = INADDR_ANY;
+    server.sin_port = htons( port );
+     
+    //Bind
+    if( bind(master ,(struct sockaddr *)&server , sizeof(server)) == SOCKET_ERROR)
+    {
+        printf("Bind failed with error code : %d" , WSAGetLastError());
+        exit(EXIT_FAILURE);
+    }
+     
+    puts("Bind done");
+ 
+    //Listen to incoming connections
+    listen(master , 3);
+     
+    //Accept and incoming connection
+    puts("Waiting for incoming connections...");
+     
+    addrlen = sizeof(struct sockaddr_in);
+     
+    while(TRUE)
+    {
+        //clear the socket fd set
+        FD_ZERO(&readfds);
+  
+        //add master socket to fd set
+        FD_SET(master, &readfds);
+         
+        //add child sockets to fd set
+        for (  i = 0 ; i < max_clients ; i++) 
+        {
+            s = client_socket[i];
+            if(s > 0)
+            {
+                FD_SET( s , &readfds);
+            }
+        }
+         
+        //wait for an activity on any of the sockets, timeout is NULL , so wait indefinitely
+        activity = select( 0 , &readfds , NULL , NULL , NULL);
+    
+        if ( activity == SOCKET_ERROR ) 
+        {
+            printf("select call failed with error code : %d" , WSAGetLastError());
+            exit(EXIT_FAILURE);
+        }
+          
+        //If something happened on the master socket , then its an incoming connection
+        if (FD_ISSET(master , &readfds)) 
+        {
+            if ((new_socket = accept(master , (struct sockaddr *)&address, (int *)&addrlen))<0)
+            {
+                perror("accept");
+                exit(EXIT_FAILURE);
+            }
+          
+            //inform user of socket number - used in send and receive commands
+            printf("New connection , socket fd is %d , ip is : %s , port : %d \n" , new_socket , inet_ntoa(address.sin_addr) , ntohs(address.sin_port));
+        
+            //send new connection greeting message
+            if( send(new_socket, message, strlen(message), 0) != strlen(message) ) 
+            {
+                perror("send failed");
+            }
+              
+            puts("Welcome message sent successfully");
+              
+            //add new socket to array of sockets
+            for (i = 0; i < max_clients; i++) 
+            {
+                if (client_socket[i] == 0)
+                {
+                    client_socket[i] = new_socket;
+                    printf("Adding to list of sockets at index %d \n" , i);
+                    break;
+                }
+            }
+        }
+          
+        //else its some IO operation on some other socket :)
+        for (i = 0; i < max_clients; i++) 
+        {
+            s = client_socket[i];
+            //if client presend in read sockets             
+            if (FD_ISSET( s , &readfds)) 
+            {
+                //get details of the client
+                getpeername(s , (struct sockaddr*)&address , (int*)&addrlen);
+ 
+                //Check if it was for closing , and also read the incoming message
+                //recv does not place a null terminator at the end of the string (whilst printf %s assumes there is one).
+                valread = recv( s , buffer, MAXRECV, 0);
+                 
+                if( valread == SOCKET_ERROR)
+                {
+                    int error_code = WSAGetLastError();
+                    if(error_code == WSAECONNRESET)
+                    {
+                        //Somebody disconnected , get his details and print
+                        printf("Host disconnected unexpectedly , ip %s , port %d \n" , inet_ntoa(address.sin_addr) , ntohs(address.sin_port));
+                      
+                        //Close the socket and mark as 0 in list for reuse
+                        closesocket( s );
+                        client_socket[i] = 0;
+                    }
+                    else
+                    {
+                        printf("recv failed with error code : %d" , error_code);
+                    }
+                }
+                if ( valread == 0)
+                {
+                    //Somebody disconnected , get his details and print
+                    printf("Host disconnected , ip %s , port %d \n" , inet_ntoa(address.sin_addr) , ntohs(address.sin_port));
+                      
+                    //Close the socket and mark as 0 in list for reuse
+                    closesocket( s );
+                    client_socket[i] = 0;
+                }
+                  
+                //Echo back the message that came in
+                else
+                {
+                    //add null character, if you want to use with printf/puts or other string handling functions
+                    buffer[valread] = '\0';
+                    printf("%s:%d - %s \n" , inet_ntoa(address.sin_addr) , ntohs(address.sin_port), buffer);
+                    send( s , buffer , valread , 0 );
+                }
+            }
+        }
+    }
+     
+    closesocket(s);
+    WSACleanup();
 
     return 0;
 }