Can anyone point me in the right direction? (C++) [SOLVED]

Iknow · 2010-11-26 07:51:43

I'm making a graphical frontend to an old MUD, the hope is to attract more players.

My main problem is that I can't find any clear telnet code and seeings as i know NOTHING about socket programming on
Micro$ft Windoze...

I'm stuck before i've even GOT to the graphics.

Last edited by Iknow (2011-02-05 02:32:38)

stfn · 2010-11-26 08:43:14

Telnet really shouldn't be the problem. MUD clients usually don't even implement the full telnet protocol but only very basic features such as for example sending and receiving plain text.

I find socket programming with the pure WinAPI to be quite ugly, so you might want to consider using portable libraries such as boost, specifically boost.asio, which offers a nice and modern way for network and IO programming in C++.

Also, you could simply use a framework like Qt which is really great for GUI programming in C++ and additionally offers everything you need for cross-platform network programming.

Vermillion · 2010-11-26 08:46:41

I can give you a short example. Wrote it a few years ago but it seems still to work (even on win 7^^).

#include <stdio.h>
#include <string.h>
#include <winsock2.h>

int startWinsock(void);

long getAddrFromString(char* hostnameOrIp, SOCKADDR_IN* addr)

{
  long rc;
  unsigned long ip;
  HOSTENT* he;
  /* Parameter prüfen */
  if(hostnameOrIp==NULL || addr==NULL)
    return SOCKET_ERROR;
  /* eine IP in hostnameOrIp ? */
  ip=inet_addr(hostnameOrIp);
  /* bei einem fehler liefert inet_addr den Rückgabewert INADDR_NONE */
  if(ip!=INADDR_NONE)
  {
    addr->sin_addr.s_addr=ip;
    return 0;
  }
  else
  {
    /* Hostname in hostnameOrIp auflösen */
    he=gethostbyname(hostnameOrIp);
    if(he==NULL)
    {
      return SOCKET_ERROR;
    }
    else
    {
      /*die 4 Bytes der IP von he nach addr kopieren */
      memcpy(&(addr->sin_addr),he->h_addr_list[0],4);
    }
    return 0;
  }
}

int main()
{
    SOCKADDR_IN addr;
    char * stringHost= (char *) malloc(1024);
    long rc;
    
    printf("Bitte Host angeben\n");
    fflush(stdin);
    stringHost=gets(stringHost);
    
    rc=startWinsock();
    if(rc!=0)
    {
        printf("Fehler: startWinsock, fehler code: %d\n",rc);
        return 1;
    }
    else
    {
        printf("Winsock gestartet!\n");
    }

    int sockfd = socket (AF_INET, SOCK_STREAM, 0);
    if (sockfd == INVALID_SOCKET) {
        printf("Fehler: Der Socket konnte nicht erstellt werden, fehler code: %d\n",WSAGetLastError());
    }

    memset(&addr,0,sizeof(SOCKADDR_IN)); // zuerst alles auf 0 setzten 
    addr.sin_family=AF_INET;
    addr.sin_port=htons(80); // wir verwenden mal port 80
    //addr.sin_addr.s_addr=inet_addr("88.198.38.248"); // zielrechner 
    
    rc=getAddrFromString(stringHost,&addr);
     if(rc==SOCKET_ERROR)
        {
            printf("IP für %s konnte nicht aufgeloest werden\n", stringHost);
            return 1;
        }
     else
        {
         printf("IP aufgeloest!\n");
        }
    
    rc=connect(sockfd,(SOCKADDR*)&addr,sizeof(SOCKADDR));
    if(rc==SOCKET_ERROR)
    {
        printf("Fehler: connect gescheitert, fehler code: %d\n",WSAGetLastError());
    }
    else
    {
        printf("Verbunden mit %s\n\n", stringHost);
    }
   
    char csend[] = "GET / HTTP/1.0\nUser-Agent: www.taldril.ch webscanner\n\n";
    /*
    printf("%s", csend);
    printf("\n");
    */
    char * buf = (char *) malloc(1024);

    for (int i = 0; i < 1024; i++)
    {
        buf[i] = 0;
    }

    char * buf2 = (char *) malloc(1024);

    for (int i = 0; i < 1024; i++)
    {
        buf2[i] = 0;
    }

    rc=send(sockfd, csend, sizeof(csend), NULL);

    if(rc==SOCKET_ERROR)
    {
        printf("Fehler: senden gescheitert, fehler code: %d\n",WSAGetLastError());
    }
    else
    {
        printf("Gesendet\n");
    }

    recv(sockfd, buf, 1024, NULL);
    recv(sockfd, buf2, 1024, NULL);
    printf("%s", buf);
    printf("%s", buf2);

    system("PAUSE");
    WSACleanup();
}

int startWinsock(void)

{

  WSADATA wsa;

  return WSAStartup(MAKEWORD(2,0),&wsa);

}

EDIT: i noticed you wanted a c++ example... i gave you C. Sorry. And there are some german comments... but i am too lazy to go through my code and translate them.

But to make your life easier take a look at the boost c++ libraries

Last edited by Vermillion (2010-11-26 08:49:32)

ewaller · 2010-11-27 02:41:51

For cross platform C++, I would go with Qt.

Iknow · 2010-11-27 18:56:57

Thanks for the replies guys, you've been a real help.
I'll check out boost and implement it as soon as i can, and Vermillion thanks for the code anyway i can translate the comments with google and my compiler has no problem with C so i'll probably be able to get the gist. I'll look up Qt but doubt i'll be using it because it is a group effort as of 2 hours after the post and i"m not responsible for graphics anymore (yay).

If i have anymore problems then i'll post them here.

ps thanks again that was a faster response than any other forum i've asked on!

Arch Linux

#1 2010-11-26 07:51:43

Can anyone point me in the right direction? (C++) [SOLVED]

#2 2010-11-26 08:43:14

Re: Can anyone point me in the right direction? (C++) [SOLVED]

#3 2010-11-26 08:46:41

Re: Can anyone point me in the right direction? (C++) [SOLVED]

#4 2010-11-27 02:41:51

Re: Can anyone point me in the right direction? (C++) [SOLVED]

#5 2010-11-27 18:56:57

Re: Can anyone point me in the right direction? (C++) [SOLVED]

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