need sockets help, stuck on problem

[manontheedge]

I've got two separate programs, one being the "server" and the other one (this one) being the "client". I've got the "server" to where it just sits and waits for connections, and sends out whatever was typed it. My problem is that this "client" code receives ONE message for the "server" and won't receive any more than that. I'm lost at this point. I've overcommented the code intentionally and took out all the error codes, because I wasn't getting any...there's no error, it's just not receiving anything more. If anyone can help me out, or tell me where I've gone wrong I would really appreciate it.

 
#include<stdio.h>
#include<winsock2.h>
#include<iostream>
using namespace std;
 
#pragma comment(lib, "ws2_32.lib")
#define STRING_MAX 2048
#define MAX 640000
#define MAX_CON 16
 
int nret;
SOCKET MySock;
 
char *client_send(char *targetip, int port)
{
 
  WSADATA wsaData;
  WORD wVersionRequested;
  wVersionRequested = MAKEWORD(2, 2);
  if(WSAStartup (wVersionRequested, &wsaData) != 0){ }
 
  MySock = socket(AF_INET, SOCK_STREAM, 0);
 
  struct sockaddr_in sock;
 
////////////////////////////////////////////////////////////////////////  
//hostent --> used by functions to store information about a given host
 
  struct hostent* target_ptr;
  if((target_ptr= gethostbyname(targetip)) == NULL){  }
 
  memcpy(&sock.sin_addr, target_ptr->h_addr, target_ptr->h_length);
  sock.sin_family= AF_INET;
  sock.sin_port=htons(port);
//////////////////////////////////////////////////////////////////////// 
 
  if((connect(MySock, (struct sockaddr *)&sock, sizeof(sock) ))){  }
 
//connect --> establishes a connection to a specified socket
//MySock --> an unconnected socket
//(struct sockaddr *)&sock -- Name of the socket in the sockaddr structure to which 
//                              the connection should be established
//sizeof(sock) -- Length of name, in bytes
 
  char *recvString= new char[MAX];
  nret = recv(MySock, recvString, MAX + 1, 0);
 
 
while(nret < 1)
{
  nret = recv(MySock, recvString, MAX + 1, 0);
//  printf("\n %d bytes received", nret);
}
 
//recv --> receives data from a connected or bound socket
//MySock -- identifies a connected socket
//recvString -- buffer for incoming data
//MAX + 1 -- The length, in bytes, of the buf parameter
//0 -- pointer flag
 
  char *output= new char[nret];
  strcpy(output, " ");
  strncat(output, recvString, nret);
  delete [ ] recvString;
 
  closesocket(MySock);
 
  WSACleanup();
 
  return (output);
 
  delete[ ] output;
}
 
 
int main(int argc, char *argv[])
{
    int port = 888;
    char* targetip;  
    char* output = NULL;
 
    targetip =  argv[1];
 
    while(1)
    {
        printf("--> ");    
        printf("%s \n", client_send(targetip, port));
    }
}
 
 
 

[gpraghuram]

Hi,
Before doing a recv call do a select and check whether there is any data available on the port for reading.
Also check whether the server is not closing the connection after sending a message to the client

Raghuram

[manontheedge]

thank you for the reply. I actually found the problem, I have some "server" and this "client" code...

I was just plane doing some things wrong. I had the server listening for connection attempts and then sending out THE message to the client. I realised my mistake, and that the client is the one that I wanted to send the message to the server. Basically, I had enough stuff backwords to make it not work right. I thought I had pinpointed the problem to the "client" code when I posted. When I realised my mistake, it only took about 30 minutes to get it running correctly.

anyway, not sure if that's gonna be clear, but thank you for the help, and, it's working fine now.