Client abnormally terminates when server isn't found

Hi there,

I just made a server and client programs (finally!!) but there's a problem with my client program. The problem is , when the server isn't up , the client abnormally terminates and displays a windows error (the one with "send report" ..etc). How do i check if the server is up , and if not , try another address for example?

here's my client's simple code :

Code:

#include <stdio.h>
#include <winsock.h>
#include <stdlib.h>
#include <windows.h>
#include <string.h>


int main(void)
{
	WSAData wsadata;
	WORD ver;
	char buffer[256];
	

	ver = MAKEWORD(1,1);

	WSAStartup(ver, &wsadata);

	LPHOSTENT hostEntry;

	hostEntry = gethostbyname("localhost");

	if(!hostEntry)
	{
		printf("Error getting host : %s\n", WSAGetLastError());
		WSACleanup();
		return 1;
	}

	printf("Host gathered ..\n");

	SOCKET theSocket;

	theSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

	if(theSocket == INVALID_SOCKET)
	{
		printf("Error socket : %s\n", WSAGetLastError());
		system("PAUSE");
		WSACleanup();
		return 1;
	}

	printf("Socket created ..\n");

	SOCKADDR_IN serverInfo;

	serverInfo.sin_family = AF_INET;
	serverInfo.sin_addr = *((LPIN_ADDR)*hostEntry->h_addr_list);
	serverInfo.sin_port = htons(666);


	if(connect(theSocket, (LPSOCKADDR)&serverInfo, 
		sizeof(sockaddr)) == -1)
	{
		printf("Error connectiog : %s", WSAGetLastError());
		WSACleanup();
		return 1;
	}

	printf("connected ... \n\n\n");



	printf("> ");

	fgets(buffer, sizeof(buffer), stdin);


	if( send(theSocket, buffer, strlen(buffer), 0) == SOCKET_ERROR)
	{
		printf("Error getting host : %s", WSAGetLastError());
		WSACleanup();
		return 1;
	}


	closesocket(theSocket);
	WSACleanup();

	return 0;
}

Edit : i forgot to mention that the program reaches "connect()" before it termiates , and it won't display an error even though i used error checking.

help is much appreciated..

Code:

	printf("Error connectiog : %s", WSAGetLastError());

WSAGetLastError does not return a string.

GAH!! stupid me *smacks forehead on table*. Turns out my error checking needs error checking .. hehe

btw , whats a good resource to learn about Asynchronous sockets? (except for Johnnie's tutorial)

This one was decent. Although I think there were a few minor errors in there if I remember correctly..

looks good JaWiB , thanks

From the tutorial :

Non-blocking sockets can be used in console apps, asynchronous sockets cannot.

*gasps* WHAT????

how come i can't use asynchronous sockets in console apps? does this force me to learn Windows programming , or is there another way around it??

Only WSAAsyncSelect requires the windows program stuff (i.e. a window procedure and message pump). Other async. methods don't.

I can only find tutorials using WSAAsyncSelect() function. Where can i find tutorials teaching the "other" methods for windows?

MSDN basically explains how to use them..

how about you name those functions so i can research them ?

Sorry -

WSAEventSelect
GetQueuedCompletionStatus with CreateIOCompletionPort
Standard blocking sockets in multiple threads is async too, because threads are async by definition.