Programming Forums > Application Development > C++

Brent · Aug 5th, 2005, 6:02 PM

#include<winsock.h>
#include<windows.h>
#include<iostream.h>
#pragma comment(lib,"wsock32.lib")

#define MAXBUFLEN 100 

void send_data();
void recv_data();

char data[500];
char rdata[MAXBUFLEN];
SOCKET server;
SOCKET client;

int main(void)
{
	WORD sockversion;
	WSADATA wsaData;
	
	int conn;

	sockversion=WSAStartup(0x101,&wsaData);
	
	if((client=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP))!=INVALID_SOCKET)
	{
		sockaddr_in server;
		server.sin_family=PF_INET;
		server.sin_port=htons(8888);
		server.sin_addr.s_addr=inet_addr("127.0.0.1");
		cout<<"connected to server\n";
		while(true)
		{
				cout<<">> ";
				cin.get(data,499);
				cin.ignore(80,'\n');
				send_data();
				recv_data();
				cout<<rdata<<endl;
		}
	}
	else
	{
		cout<<"invalid socket\n";
		WSACleanup();
		return 0;
	}
}

void send_data()
{
	int sent;

	sockaddr_in to;
	to.sin_family=PF_INET;
	to.sin_port=htons(8888);
	to.sin_addr.s_addr=inet_addr("127.0.0.1");
	
	sent=sendto(client,data,sizeof(data),0,(struct sockaddr*)&to,sizeof(to));
}


void recv_data()
{
	int addr_len;
	addr_len=sizeof(struct sockaddr); 
	
	sockaddr_in fro;
	fro.sin_family=PF_INET;
	fro.sin_port=htons(8888);
	fro.sin_addr.s_addr=inet_addr("127.0.0.1");
	
	recvfrom(client,rdata,MAXBUFLEN-1,0,(struct sockaddr*)&fro,&addr_len);
}

I have created a simple UDP program and was wondering if anyone could just look it over and give me some suggestions to make it work better.

prolog · Aug 5th, 2005, 6:42 PM

Hi,

just a note. Wouldn't it be nice to shutdown the application cracefully via userinput ?
I didn't look into detail in the rest of the code as i'm too tired right now to be any helpful. I'll look over it again tomorrow if you like.

so far ...

Brent · Aug 5th, 2005, 6:58 PM

how do you use "userinput"?

prolog · Aug 5th, 2005, 7:02 PM

was it the wrong word ? I meant that one should probably be able to type "quit" or "exit" or something an you applications shuts down in consequence of this input.

Brent · Aug 5th, 2005, 8:00 PM

how would i do this?

Brent · Aug 5th, 2005, 8:10 PM

here is what i came up with:

(Toggle Plain Text)

#include<winsock.h>
#include<windows.h>
#include<iostream.h>
#pragma comment(lib,"wsock32.lib")
#define MAXBUFLEN 100 

void send_data();
void recv_data();
void quit();

char data[500];
char rdata[MAXBUFLEN];
SOCKET server;
SOCKET client;

int main(void)
{
	WORD sockversion;
	WSADATA wsaData;
	
	int conn;

	sockversion=WSAStartup(0x101,&wsaData);
	
	if((client=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP))!=INVALID_SOCKET)
	{
		sockaddr_in server;
		server.sin_family=PF_INET;
		server.sin_port=htons(8888);
		server.sin_addr.s_addr=inet_addr("127.0.0.1");
		cout<<"connected to server\n";
		while(true)
		{
			char escape[5]="quit";
			cout<<">> ";
			cin.get(data,499);
			cin.ignore(80,'\n');
			if(strcmp(rdata,escape)==0)
			{
				quit();
			}
			send_data();
			recv_data();
			cout<<rdata<<endl;
		}
	}
	else
	{
		cout<<"invalid socket\n";
		WSACleanup();
		return 0;
	}
}

void send_data()
{
	int sent;

	sockaddr_in to;
	to.sin_family=PF_INET;
	to.sin_port=htons(8888);
	to.sin_addr.s_addr=inet_addr("127.0.0.1");
	
	if((sendto(client,data,sizeof(data),0,(struct sockaddr*)&to,sizeof(to)))==SOCKET_ERROR)
	{
		cout<<"failed send\n";
		WSACleanup();
	}
}

void recv_data()
{
	int addr_len;
	addr_len=sizeof(struct sockaddr); 
	
	sockaddr_in fro;
	fro.sin_family=PF_INET;
	fro.sin_port=htons(8888);
	fro.sin_addr.s_addr=inet_addr("127.0.0.1");
	
	if((recvfrom(client,rdata,MAXBUFLEN-1,0,(struct sockaddr*)&fro,&addr_len))==SOCKET_ERROR)
	{
		int error=WSAGetLastError();
		if(error==WSAENOTSOCK)
		{
			cout<<"not a valid socket\n";
			WSACleanup();
		}
		else if(error==WSAENOTCONN)
		{
			cout<<"socket not connected\n";
			WSACleanup();
		}
		cout<<"failed recv\n";
		WSACleanup();
	}
}

void quit()
{
	cout<<"goodbye\n";
	WSACleanup();
	closesocket(client);
	closesocket(server);
}

Brent · Aug 6th, 2005, 5:59 PM

the last post didnt work so I made a few changes:

(Toggle Plain Text)

#include<winsock.h>
#include<windows.h>
#include<iostream.h>
#include<stdlib.h>
#pragma comment(lib,"wsock32.lib")
#define MAXBUFLEN 100 

void send_data();
void recv_data();

char data[500];
char rdata[MAXBUFLEN];
SOCKET server;
SOCKET client;

int main(void)
{
	WORD sockversion;
	WSADATA wsaData;
	
	int conn;

	sockversion=WSAStartup(0x101,&wsaData);
	
	if((client=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP))!=INVALID_SOCKET)
	{
		sockaddr_in server;
		server.sin_family=PF_INET;
		server.sin_port=htons(19783);
		server.sin_addr.s_addr=inet_addr("127.0.0.1");
		cout<<"connected to server\n";
		while(true)
		{
			char escape[5]="-q";
			char ip_addr[5]="-ip";
			char clear[5]="clear";
			sockaddr_in from;
			int fromlen=sizeof(from);
		
			cout<<">> ";
			cin.get(data,499);
			cin.ignore(80,'\n');
			if(strcmp(data,escape)==0)
			{
				WSACleanup();
				closesocket(client);
				return 0;
			}
			else if(strcmp(data,ip_addr)==0)
			{
				cout<<"<server IP> "<<inet_ntoa(from.sin_addr)<<endl;
			}
			else
			{
				send_data();
				recv_data();
				cout<<rdata<<endl;
			}
		}
	}
	else
	{
		cout<<"invalid socket\n";
		WSACleanup();
		return 0;
	}
}

void send_data()
{
	int sent;

	sockaddr_in to;
	to.sin_family=PF_INET;
	to.sin_port=htons(19783);
	to.sin_addr.s_addr=inet_addr("127.0.0.1");
	
	if((sendto(client,data,sizeof(data),0,(struct sockaddr*)&to,sizeof(to)))==SOCKET_ERROR)
	{
		cout<<"failed send\n";
		WSACleanup();
	}
}

void recv_data()
{
	int addr_len;
	addr_len=sizeof(struct sockaddr); 
	
	sockaddr_in fro;
	fro.sin_family=PF_INET;
	fro.sin_port=htons(19783);
	fro.sin_addr.s_addr=inet_addr("127.0.0.1");
	
	if((recvfrom(client,rdata,MAXBUFLEN-1,0,(struct sockaddr*)&fro,&addr_len))==SOCKET_ERROR)
	{
		int error=WSAGetLastError();
		if(error==WSAENOTSOCK)
		{
			cout<<"not a valid socket\n";
			WSACleanup();
		}
		else if(error==WSAENOTCONN)
		{
			cout<<"socket not connected\n";
			WSACleanup();
		}
		cout<<"failed recv\n";
		WSACleanup();
	}
}

what I did was create a char array named escape[5]="-q", and if the user input was equal to escape then it would close the socket, and return 0.

now I have another question. Could someone show me how to use select in this program. I want to make it so the program can send and receive data at the same time to make it more efficient. I have read countless tutorials including Beej's tutorial, and I cant seem to figure it out. Im sure its just something stupid, but any help would be greatly appreciated.

Brent · Aug 7th, 2005, 6:10 PM

I had some free time last night so I revised it again:

(Toggle Plain Text)

#include<winsock.h>
#include<windows.h>
#include<iostream.h>
#include<stdlib.h>
#include<fstream.h>
#pragma comment(lib,"wsock32.lib")
#define MAXBUFLEN 500

void send_recv();

char rdata[MAXBUFLEN];
char data[500];

SOCKET client;
SOCKET server;

int main(void)
{
	WORD sockversion;
	WSADATA wsaData;
	int conn;

	if((sockversion=WSAStartup(0x101,&wsaData))!=SOCKET_ERROR)
	{	
		if((client=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP))!=INVALID_SOCKET)
		{
			sockaddr_in from;
			int fromlen=sizeof(from);
			
			sockaddr_in to;
			to.sin_family=AF_INET;
			to.sin_port=htons(8888);
			to.sin_addr.s_addr=inet_addr("127.0.0.1");
			
			if(connect(client,(LPSOCKADDR)&to,sizeof(to))!=SOCKET_ERROR)
			{	
				cout<<"\n";
				cout<<"connected to server\n";
				cout<<"\n";
				cout<<"------------------------------\n";
				cout<<"welcome to brents chat program\n";
				cout<<"------------------------------\n";
				cout<<"-hlp for help\n";
				cout<<"\n";
			
				while(true)
				{
					char escape[5]="-q";
					char ip_addr[5]="-ip";
					char clear[5]="-clr";
					char help[5]="-hlp";
					char disconn[5]="-dis";
				
					cout<<">> ";
					cin.get(data,499);
					cin.ignore(80,'\n');		
					if(strcmp(data,escape)==0)
					{
						WSACleanup();
						closesocket(client);
						return 0;
					}
					else if(strcmp(data,ip_addr)==0)
					{
						cout<<"\n";
						cout<<"<server IP: "<<inet_ntoa(from.sin_addr)<<"> "<<'\n';
						cout<<"<server port: "<<htons(from.sin_port)<<">"<<'\n';
						cout<<"\n";
					}
					else if(strcmp(data,clear)==0)
					{
						system("cls");
					}
					else if(strcmp(data,help)==0)
					{
						cout<<"\n";
						cout<<"-q   quit\n";
						cout<<"-clr clear screen\n";
						cout<<"-ip  get server IP and port #\n";
						cout<<"-dis disconnect from server\n";
						cout<<"\n";
					}
					else if(strcmp(data,disconn)==0)
					{
						cout<<"\n";
						cout<<"you have disconnected\n";
						closesocket(server);
						closesocket(client);
						WSACleanup();
						cout<<"\n";
					}
					else
					{
						send_recv();
						cout<<rdata<<endl;
					}				
				}
			}
			else
			{
				cout<<"failed to connect to server\n";
				closesocket(client);
				WSACleanup();
			}
		}
		else
		{
			cout<<"invalid socket\n";
			WSACleanup();
			return 0;
		}
	}
	else
	{
		cout<<"WSAStartup() failed\n";
		WSACleanup();
		return 0;	
	}
}

void send_recv()
{
	int sent;
	
	sockaddr_in to;
	to.sin_family=AF_INET;
	to.sin_port=htons(8888);
	to.sin_addr.s_addr=inet_addr("127.0.0.1");
	
	if((sendto(client,data,sizeof(data),0,(LPSOCKADDR)&to,sizeof(to)))==SOCKET_ERROR)
	{
		cout<<"failed send\n";
		WSACleanup();
	}
	
	int addr_len;
	addr_len=sizeof(struct sockaddr*); 
	
	sockaddr_in fro;
	fro.sin_family=AF_INET;
	fro.sin_port=htons(8888);
	fro.sin_addr.s_addr=inet_addr("127.0.0.1");
	
	if((recvfrom(server,rdata,MAXBUFLEN-1,0,(LPSOCKADDR)&fro,&addr_len))==SOCKET_ERROR)
	{
		int error=WSAGetLastError();
		if(error==WSAENOTSOCK)
		{
			cout<<"not a valid socket\n";
			WSACleanup();
		}
		else if(error==WSAENOTCONN)
		{
			cout<<"socket not connected\n";
			WSACleanup();
		}
		cout<<"failed recv\n";
		WSACleanup();
	}
	else
	{
		cout<<"server says: "<<rdata<<'\n';
	}
}

#include<winsock.h>
#include<windows.h>
#include<iostream.h>
#include<stdlib.h>
#include<fstream.h>
#pragma comment(lib,"wsock32.lib")
#define MAXBUFLEN 500

void send_recv();

char rdata[MAXBUFLEN];
char data[500];

SOCKET client;
SOCKET server;

int main(void)
{
	WORD sockversion;
	WSADATA wsaData;
	int conn;

	if((sockversion=WSAStartup(0x101,&wsaData))!=SOCKET_ERROR)
	{	
		if((client=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP))!=INVALID_SOCKET)
		{
			sockaddr_in from;
			int fromlen=sizeof(from);
			
			sockaddr_in to;
			to.sin_family=AF_INET;
			to.sin_port=htons(8888);
			to.sin_addr.s_addr=inet_addr("127.0.0.1");
			
			if(connect(client,(LPSOCKADDR)&to,sizeof(to))!=SOCKET_ERROR)
			{	
				cout<<"\n";
				cout<<"connected to server\n";
				cout<<"\n";
				cout<<"------------------------------\n";
				cout<<"welcome to brents chat program\n";
				cout<<"------------------------------\n";
				cout<<"-hlp for help\n";
				cout<<"\n";
			
				while(true)
				{
					char escape[5]="-q";
					char ip_addr[5]="-ip";
					char clear[5]="-clr";
					char help[5]="-hlp";
					char disconn[5]="-dis";
				
					cout<<">> ";
					cin.get(data,499);
					cin.ignore(80,'\n');		
					if(strcmp(data,escape)==0)
					{
						WSACleanup();
						closesocket(client);
						return 0;
					}
					else if(strcmp(data,ip_addr)==0)
					{
						cout<<"\n";
						cout<<"<server IP: "<<inet_ntoa(from.sin_addr)<<"> "<<'\n';
						cout<<"<server port: "<<htons(from.sin_port)<<">"<<'\n';
						cout<<"\n";
					}
					else if(strcmp(data,clear)==0)
					{
						system("cls");
					}
					else if(strcmp(data,help)==0)
					{
						cout<<"\n";
						cout<<"-q   quit\n";
						cout<<"-clr clear screen\n";
						cout<<"-ip  get server IP and port #\n";
						cout<<"-dis disconnect from server\n";
						cout<<"\n";
					}
					else if(strcmp(data,disconn)==0)
					{
						cout<<"\n";
						cout<<"you have disconnected\n";
						closesocket(server);
						closesocket(client);
						WSACleanup();
						cout<<"\n";
					}
					else
					{
						send_recv();
						cout<<rdata<<endl;
					}				
				}
			}
			else
			{
				cout<<"failed to connect to server\n";
				closesocket(client);
				WSACleanup();
			}
		}
		else
		{
			cout<<"invalid socket\n";
			WSACleanup();
			return 0;
		}
	}
	else
	{
		cout<<"WSAStartup() failed\n";
		WSACleanup();
		return 0;	
	}
}

void send_recv()
{
	int sent;
	
	sockaddr_in to;
	to.sin_family=AF_INET;
	to.sin_port=htons(8888);
	to.sin_addr.s_addr=inet_addr("127.0.0.1");
	
	if((sendto(client,data,sizeof(data),0,(LPSOCKADDR)&to,sizeof(to)))==SOCKET_ERROR)
	{
		cout<<"failed send\n";
		WSACleanup();
	}
	
	int addr_len;
	addr_len=sizeof(struct sockaddr*); 
	
	sockaddr_in fro;
	fro.sin_family=AF_INET;
	fro.sin_port=htons(8888);
	fro.sin_addr.s_addr=inet_addr("127.0.0.1");
	
	if((recvfrom(server,rdata,MAXBUFLEN-1,0,(LPSOCKADDR)&fro,&addr_len))==SOCKET_ERROR)
	{
		int error=WSAGetLastError();
		if(error==WSAENOTSOCK)
		{
			cout<<"not a valid socket\n";
			WSACleanup();
		}
		else if(error==WSAENOTCONN)
		{
			cout<<"socket not connected\n";
			WSACleanup();
		}
		cout<<"failed recv\n";
		WSACleanup();
	}
	else
	{
		cout<<"server says: "<<rdata<<'\n';
	}
}

I made a few more changes:

1) added to the menu
2)combined the send_data() and recv_data() functions
and created the send_recv() function
3)I created the socket using PF_INET and filled sockaddr_in with AF_INET

if anyone has any suggestions that would improve this program please tell me, any help would be greatly appreciated.

Shapeless · Aug 7th, 2005, 6:30 PM

hhm, this is not going to help you at all, but i would recommend to use standard headers.
so dont use

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<iostream.h>
<stdlib.h>
<fstream.h>

but

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<iostream>
<cstdlib>
<fstream>

as well as the std namespace.

stop useing

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#define

and use

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const type=blubb;

that means in your case

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static const int max_buflen=500;

as it is written in Scott Meyers's : Effective C++ ( Item 1: Prefer const and inline to #define)

Brent · Aug 9th, 2005, 1:58 PM

I also have another problem. when I send the message to the server, it doesnt send. I am using the same code as above.

Aug 5th, 2005, 6:02 PM	#1
Brent Highly Adaptive Penguin Join Date: May 2005 Location: United States Posts: 251 Rep Power: 4	UDP network application (Toggle Plain Text) #include<winsock.h> #include<windows.h> #include<iostream.h> #pragma comment(lib,"wsock32.lib") #define MAXBUFLEN 100 void send_data(); void recv_data(); char data[500]; char rdata[MAXBUFLEN]; SOCKET server; SOCKET client; int main(void) { WORD sockversion; WSADATA wsaData; int conn; sockversion=WSAStartup(0x101,&wsaData); if((client=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP))!=INVALID_SOCKET) { sockaddr_in server; server.sin_family=PF_INET; server.sin_port=htons(8888); server.sin_addr.s_addr=inet_addr("127.0.0.1"); cout<<"connected to server\n"; while(true) { cout<<">> "; cin.get(data,499); cin.ignore(80,'\n'); send_data(); recv_data(); cout<<rdata<<endl; } } else { cout<<"invalid socket\n"; WSACleanup(); return 0; } } void send_data() { int sent; sockaddr_in to; to.sin_family=PF_INET; to.sin_port=htons(8888); to.sin_addr.s_addr=inet_addr("127.0.0.1"); sent=sendto(client,data,sizeof(data),0,(struct sockaddr)&to,sizeof(to)); } void recv_data() { int addr_len; addr_len=sizeof(struct sockaddr); sockaddr_in fro; fro.sin_family=PF_INET; fro.sin_port=htons(8888); fro.sin_addr.s_addr=inet_addr("127.0.0.1"); recvfrom(client,rdata,MAXBUFLEN-1,0,(struct sockaddr)&fro,&addr_len); } #include<winsock.h> #include<windows.h> #include<iostream.h> #pragma comment(lib,"wsock32.lib") #define MAXBUFLEN 100 void send_data(); void recv_data(); char data[500]; char rdata[MAXBUFLEN]; SOCKET server; SOCKET client; int main(void) { WORD sockversion; WSADATA wsaData; int conn; sockversion=WSAStartup(0x101,&wsaData); if((client=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP))!=INVALID_SOCKET) { sockaddr_in server; server.sin_family=PF_INET; server.sin_port=htons(8888); server.sin_addr.s_addr=inet_addr("127.0.0.1"); cout<<"connected to server\n"; while(true) { cout<<">> "; cin.get(data,499); cin.ignore(80,'\n'); send_data(); recv_data(); cout<<rdata<<endl; } } else { cout<<"invalid socket\n"; WSACleanup(); return 0; } } void send_data() { int sent; sockaddr_in to; to.sin_family=PF_INET; to.sin_port=htons(8888); to.sin_addr.s_addr=inet_addr("127.0.0.1"); sent=sendto(client,data,sizeof(data),0,(struct sockaddr)&to,sizeof(to)); } void recv_data() { int addr_len; addr_len=sizeof(struct sockaddr); sockaddr_in fro; fro.sin_family=PF_INET; fro.sin_port=htons(8888); fro.sin_addr.s_addr=inet_addr("127.0.0.1"); recvfrom(client,rdata,MAXBUFLEN-1,0,(struct sockaddr)&fro,&addr_len); } I have created a simple UDP program and was wondering if anyone could just look it over and give me some suggestions to make it work better.

Aug 5th, 2005, 6:42 PM	#2
prolog Programmer Join Date: Jul 2005 Location: Germany Posts: 69 Rep Power: 4	Hi, just a note. Wouldn't it be nice to shutdown the application cracefully via userinput ? I didn't look into detail in the rest of the code as i'm too tired right now to be any helpful. I'll look over it again tomorrow if you like. so far ... __________________ -= C makes it easy to shoot yourself in the foot; C++ makes it harder, but when you do succeed, you will blow away your whole leg. =- Bjarne Stroustrup

Aug 5th, 2005, 7:02 PM	#4
prolog Programmer Join Date: Jul 2005 Location: Germany Posts: 69 Rep Power: 4	was it the wrong word ? I meant that one should probably be able to type "quit" or "exit" or something an you applications shuts down in consequence of this input. __________________ -= C makes it easy to shoot yourself in the foot; C++ makes it harder, but when you do succeed, you will blow away your whole leg. =- Bjarne Stroustrup

Aug 5th, 2005, 8:10 PM	#6
Brent Highly Adaptive Penguin Join Date: May 2005 Location: United States Posts: 251 Rep Power: 4	here is what i came up with: (Toggle Plain Text) #include<winsock.h> #include<windows.h> #include<iostream.h> #pragma comment(lib,"wsock32.lib") #define MAXBUFLEN 100 void send_data(); void recv_data(); void quit(); char data[500]; char rdata[MAXBUFLEN]; SOCKET server; SOCKET client; int main(void) { WORD sockversion; WSADATA wsaData; int conn; sockversion=WSAStartup(0x101,&wsaData); if((client=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP))!=INVALID_SOCKET) { sockaddr_in server; server.sin_family=PF_INET; server.sin_port=htons(8888); server.sin_addr.s_addr=inet_addr("127.0.0.1"); cout<<"connected to server\n"; while(true) { char escape[5]="quit"; cout<<">> "; cin.get(data,499); cin.ignore(80,'\n'); if(strcmp(rdata,escape)==0) { quit(); } send_data(); recv_data(); cout<<rdata<<endl; } } else { cout<<"invalid socket\n"; WSACleanup(); return 0; } } void send_data() { int sent; sockaddr_in to; to.sin_family=PF_INET; to.sin_port=htons(8888); to.sin_addr.s_addr=inet_addr("127.0.0.1"); if((sendto(client,data,sizeof(data),0,(struct sockaddr)&to,sizeof(to)))==SOCKET_ERROR) { cout<<"failed send\n"; WSACleanup(); } } void recv_data() { int addr_len; addr_len=sizeof(struct sockaddr); sockaddr_in fro; fro.sin_family=PF_INET; fro.sin_port=htons(8888); fro.sin_addr.s_addr=inet_addr("127.0.0.1"); if((recvfrom(client,rdata,MAXBUFLEN-1,0,(struct sockaddr)&fro,&addr_len))==SOCKET_ERROR) { int error=WSAGetLastError(); if(error==WSAENOTSOCK) { cout<<"not a valid socket\n"; WSACleanup(); } else if(error==WSAENOTCONN) { cout<<"socket not connected\n"; WSACleanup(); } cout<<"failed recv\n"; WSACleanup(); } } void quit() { cout<<"goodbye\n"; WSACleanup(); closesocket(client); closesocket(server); } #include<winsock.h> #include<windows.h> #include<iostream.h> #pragma comment(lib,"wsock32.lib") #define MAXBUFLEN 100 void send_data(); void recv_data(); void quit(); char data[500]; char rdata[MAXBUFLEN]; SOCKET server; SOCKET client; int main(void) { WORD sockversion; WSADATA wsaData; int conn; sockversion=WSAStartup(0x101,&wsaData); if((client=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP))!=INVALID_SOCKET) { sockaddr_in server; server.sin_family=PF_INET; server.sin_port=htons(8888); server.sin_addr.s_addr=inet_addr("127.0.0.1"); cout<<"connected to server\n"; while(true) { char escape[5]="quit"; cout<<">> "; cin.get(data,499); cin.ignore(80,'\n'); if(strcmp(rdata,escape)==0) { quit(); } send_data(); recv_data(); cout<<rdata<<endl; } } else { cout<<"invalid socket\n"; WSACleanup(); return 0; } } void send_data() { int sent; sockaddr_in to; to.sin_family=PF_INET; to.sin_port=htons(8888); to.sin_addr.s_addr=inet_addr("127.0.0.1"); if((sendto(client,data,sizeof(data),0,(struct sockaddr)&to,sizeof(to)))==SOCKET_ERROR) { cout<<"failed send\n"; WSACleanup(); } } void recv_data() { int addr_len; addr_len=sizeof(struct sockaddr); sockaddr_in fro; fro.sin_family=PF_INET; fro.sin_port=htons(8888); fro.sin_addr.s_addr=inet_addr("127.0.0.1"); if((recvfrom(client,rdata,MAXBUFLEN-1,0,(struct sockaddr)&fro,&addr_len))==SOCKET_ERROR) { int error=WSAGetLastError(); if(error==WSAENOTSOCK) { cout<<"not a valid socket\n"; WSACleanup(); } else if(error==WSAENOTCONN) { cout<<"socket not connected\n"; WSACleanup(); } cout<<"failed recv\n"; WSACleanup(); } } void quit() { cout<<"goodbye\n"; WSACleanup(); closesocket(client); closesocket(server); }

Aug 6th, 2005, 5:59 PM	#7
Brent Highly Adaptive Penguin Join Date: May 2005 Location: United States Posts: 251 Rep Power: 4	the last post didnt work so I made a few changes: (Toggle Plain Text) #include<winsock.h> #include<windows.h> #include<iostream.h> #include<stdlib.h> #pragma comment(lib,"wsock32.lib") #define MAXBUFLEN 100 void send_data(); void recv_data(); char data[500]; char rdata[MAXBUFLEN]; SOCKET server; SOCKET client; int main(void) { WORD sockversion; WSADATA wsaData; int conn; sockversion=WSAStartup(0x101,&wsaData); if((client=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP))!=INVALID_SOCKET) { sockaddr_in server; server.sin_family=PF_INET; server.sin_port=htons(19783); server.sin_addr.s_addr=inet_addr("127.0.0.1"); cout<<"connected to server\n"; while(true) { char escape[5]="-q"; char ip_addr[5]="-ip"; char clear[5]="clear"; sockaddr_in from; int fromlen=sizeof(from); cout<<">> "; cin.get(data,499); cin.ignore(80,'\n'); if(strcmp(data,escape)==0) { WSACleanup(); closesocket(client); return 0; } else if(strcmp(data,ip_addr)==0) { cout<<"<server IP> "<<inet_ntoa(from.sin_addr)<<endl; } else { send_data(); recv_data(); cout<<rdata<<endl; } } } else { cout<<"invalid socket\n"; WSACleanup(); return 0; } } void send_data() { int sent; sockaddr_in to; to.sin_family=PF_INET; to.sin_port=htons(19783); to.sin_addr.s_addr=inet_addr("127.0.0.1"); if((sendto(client,data,sizeof(data),0,(struct sockaddr)&to,sizeof(to)))==SOCKET_ERROR) { cout<<"failed send\n"; WSACleanup(); } } void recv_data() { int addr_len; addr_len=sizeof(struct sockaddr); sockaddr_in fro; fro.sin_family=PF_INET; fro.sin_port=htons(19783); fro.sin_addr.s_addr=inet_addr("127.0.0.1"); if((recvfrom(client,rdata,MAXBUFLEN-1,0,(struct sockaddr)&fro,&addr_len))==SOCKET_ERROR) { int error=WSAGetLastError(); if(error==WSAENOTSOCK) { cout<<"not a valid socket\n"; WSACleanup(); } else if(error==WSAENOTCONN) { cout<<"socket not connected\n"; WSACleanup(); } cout<<"failed recv\n"; WSACleanup(); } } #include<winsock.h> #include<windows.h> #include<iostream.h> #include<stdlib.h> #pragma comment(lib,"wsock32.lib") #define MAXBUFLEN 100 void send_data(); void recv_data(); char data[500]; char rdata[MAXBUFLEN]; SOCKET server; SOCKET client; int main(void) { WORD sockversion; WSADATA wsaData; int conn; sockversion=WSAStartup(0x101,&wsaData); if((client=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP))!=INVALID_SOCKET) { sockaddr_in server; server.sin_family=PF_INET; server.sin_port=htons(19783); server.sin_addr.s_addr=inet_addr("127.0.0.1"); cout<<"connected to server\n"; while(true) { char escape[5]="-q"; char ip_addr[5]="-ip"; char clear[5]="clear"; sockaddr_in from; int fromlen=sizeof(from); cout<<">> "; cin.get(data,499); cin.ignore(80,'\n'); if(strcmp(data,escape)==0) { WSACleanup(); closesocket(client); return 0; } else if(strcmp(data,ip_addr)==0) { cout<<"<server IP> "<<inet_ntoa(from.sin_addr)<<endl; } else { send_data(); recv_data(); cout<<rdata<<endl; } } } else { cout<<"invalid socket\n"; WSACleanup(); return 0; } } void send_data() { int sent; sockaddr_in to; to.sin_family=PF_INET; to.sin_port=htons(19783); to.sin_addr.s_addr=inet_addr("127.0.0.1"); if((sendto(client,data,sizeof(data),0,(struct sockaddr)&to,sizeof(to)))==SOCKET_ERROR) { cout<<"failed send\n"; WSACleanup(); } } void recv_data() { int addr_len; addr_len=sizeof(struct sockaddr); sockaddr_in fro; fro.sin_family=PF_INET; fro.sin_port=htons(19783); fro.sin_addr.s_addr=inet_addr("127.0.0.1"); if((recvfrom(client,rdata,MAXBUFLEN-1,0,(struct sockaddr)&fro,&addr_len))==SOCKET_ERROR) { int error=WSAGetLastError(); if(error==WSAENOTSOCK) { cout<<"not a valid socket\n"; WSACleanup(); } else if(error==WSAENOTCONN) { cout<<"socket not connected\n"; WSACleanup(); } cout<<"failed recv\n"; WSACleanup(); } } what I did was create a char array named escape[5]="-q", and if the user input was equal to escape then it would close the socket, and return 0. now I have another question. Could someone show me how to use select in this program. I want to make it so the program can send and receive data at the same time to make it more efficient. I have read countless tutorials including Beej's tutorial, and I cant seem to figure it out. Im sure its just something stupid, but any help would be greatly appreciated.

Aug 5th, 2005, 6:58 PM	#3
Brent Highly Adaptive Penguin Join Date: May 2005 Location: United States Posts: 251 Rep Power: 4	how do you use "userinput"?

Aug 5th, 2005, 8:00 PM	#5
Brent Highly Adaptive Penguin Join Date: May 2005 Location: United States Posts: 251 Rep Power: 4	how would i do this?

Aug 7th, 2005, 6:10 PM	#8
Brent Highly Adaptive Penguin Join Date: May 2005 Location: United States Posts: 251 Rep Power: 4	I had some free time last night so I revised it again: (Toggle Plain Text) #include<winsock.h> #include<windows.h> #include<iostream.h> #include<stdlib.h> #include<fstream.h> #pragma comment(lib,"wsock32.lib") #define MAXBUFLEN 500 void send_recv(); char rdata[MAXBUFLEN]; char data[500]; SOCKET client; SOCKET server; int main(void) { WORD sockversion; WSADATA wsaData; int conn; if((sockversion=WSAStartup(0x101,&wsaData))!=SOCKET_ERROR) { if((client=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP))!=INVALID_SOCKET) { sockaddr_in from; int fromlen=sizeof(from); sockaddr_in to; to.sin_family=AF_INET; to.sin_port=htons(8888); to.sin_addr.s_addr=inet_addr("127.0.0.1"); if(connect(client,(LPSOCKADDR)&to,sizeof(to))!=SOCKET_ERROR) { cout<<"\n"; cout<<"connected to server\n"; cout<<"\n"; cout<<"------------------------------\n"; cout<<"welcome to brents chat program\n"; cout<<"------------------------------\n"; cout<<"-hlp for help\n"; cout<<"\n"; while(true) { char escape[5]="-q"; char ip_addr[5]="-ip"; char clear[5]="-clr"; char help[5]="-hlp"; char disconn[5]="-dis"; cout<<">> "; cin.get(data,499); cin.ignore(80,'\n'); if(strcmp(data,escape)==0) { WSACleanup(); closesocket(client); return 0; } else if(strcmp(data,ip_addr)==0) { cout<<"\n"; cout<<"<server IP: "<<inet_ntoa(from.sin_addr)<<"> "<<'\n'; cout<<"<server port: "<<htons(from.sin_port)<<">"<<'\n'; cout<<"\n"; } else if(strcmp(data,clear)==0) { system("cls"); } else if(strcmp(data,help)==0) { cout<<"\n"; cout<<"-q quit\n"; cout<<"-clr clear screen\n"; cout<<"-ip get server IP and port #\n"; cout<<"-dis disconnect from server\n"; cout<<"\n"; } else if(strcmp(data,disconn)==0) { cout<<"\n"; cout<<"you have disconnected\n"; closesocket(server); closesocket(client); WSACleanup(); cout<<"\n"; } else { send_recv(); cout<<rdata<<endl; } } } else { cout<<"failed to connect to server\n"; closesocket(client); WSACleanup(); } } else { cout<<"invalid socket\n"; WSACleanup(); return 0; } } else { cout<<"WSAStartup() failed\n"; WSACleanup(); return 0; } } void send_recv() { int sent; sockaddr_in to; to.sin_family=AF_INET; to.sin_port=htons(8888); to.sin_addr.s_addr=inet_addr("127.0.0.1"); if((sendto(client,data,sizeof(data),0,(LPSOCKADDR)&to,sizeof(to)))==SOCKET_ERROR) { cout<<"failed send\n"; WSACleanup(); } int addr_len; addr_len=sizeof(struct sockaddr); sockaddr_in fro; fro.sin_family=AF_INET; fro.sin_port=htons(8888); fro.sin_addr.s_addr=inet_addr("127.0.0.1"); if((recvfrom(server,rdata,MAXBUFLEN-1,0,(LPSOCKADDR)&fro,&addr_len))==SOCKET_ERROR) { int error=WSAGetLastError(); if(error==WSAENOTSOCK) { cout<<"not a valid socket\n"; WSACleanup(); } else if(error==WSAENOTCONN) { cout<<"socket not connected\n"; WSACleanup(); } cout<<"failed recv\n"; WSACleanup(); } else { cout<<"server says: "<<rdata<<'\n'; } } #include<winsock.h> #include<windows.h> #include<iostream.h> #include<stdlib.h> #include<fstream.h> #pragma comment(lib,"wsock32.lib") #define MAXBUFLEN 500 void send_recv(); char rdata[MAXBUFLEN]; char data[500]; SOCKET client; SOCKET server; int main(void) { WORD sockversion; WSADATA wsaData; int conn; if((sockversion=WSAStartup(0x101,&wsaData))!=SOCKET_ERROR) { if((client=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP))!=INVALID_SOCKET) { sockaddr_in from; int fromlen=sizeof(from); sockaddr_in to; to.sin_family=AF_INET; to.sin_port=htons(8888); to.sin_addr.s_addr=inet_addr("127.0.0.1"); if(connect(client,(LPSOCKADDR)&to,sizeof(to))!=SOCKET_ERROR) { cout<<"\n"; cout<<"connected to server\n"; cout<<"\n"; cout<<"------------------------------\n"; cout<<"welcome to brents chat program\n"; cout<<"------------------------------\n"; cout<<"-hlp for help\n"; cout<<"\n"; while(true) { char escape[5]="-q"; char ip_addr[5]="-ip"; char clear[5]="-clr"; char help[5]="-hlp"; char disconn[5]="-dis"; cout<<">> "; cin.get(data,499); cin.ignore(80,'\n'); if(strcmp(data,escape)==0) { WSACleanup(); closesocket(client); return 0; } else if(strcmp(data,ip_addr)==0) { cout<<"\n"; cout<<"<server IP: "<<inet_ntoa(from.sin_addr)<<"> "<<'\n'; cout<<"<server port: "<<htons(from.sin_port)<<">"<<'\n'; cout<<"\n"; } else if(strcmp(data,clear)==0) { system("cls"); } else if(strcmp(data,help)==0) { cout<<"\n"; cout<<"-q quit\n"; cout<<"-clr clear screen\n"; cout<<"-ip get server IP and port #\n"; cout<<"-dis disconnect from server\n"; cout<<"\n"; } else if(strcmp(data,disconn)==0) { cout<<"\n"; cout<<"you have disconnected\n"; closesocket(server); closesocket(client); WSACleanup(); cout<<"\n"; } else { send_recv(); cout<<rdata<<endl; } } } else { cout<<"failed to connect to server\n"; closesocket(client); WSACleanup(); } } else { cout<<"invalid socket\n"; WSACleanup(); return 0; } } else { cout<<"WSAStartup() failed\n"; WSACleanup(); return 0; } } void send_recv() { int sent; sockaddr_in to; to.sin_family=AF_INET; to.sin_port=htons(8888); to.sin_addr.s_addr=inet_addr("127.0.0.1"); if((sendto(client,data,sizeof(data),0,(LPSOCKADDR)&to,sizeof(to)))==SOCKET_ERROR) { cout<<"failed send\n"; WSACleanup(); } int addr_len; addr_len=sizeof(struct sockaddr); sockaddr_in fro; fro.sin_family=AF_INET; fro.sin_port=htons(8888); fro.sin_addr.s_addr=inet_addr("127.0.0.1"); if((recvfrom(server,rdata,MAXBUFLEN-1,0,(LPSOCKADDR)&fro,&addr_len))==SOCKET_ERROR) { int error=WSAGetLastError(); if(error==WSAENOTSOCK) { cout<<"not a valid socket\n"; WSACleanup(); } else if(error==WSAENOTCONN) { cout<<"socket not connected\n"; WSACleanup(); } cout<<"failed recv\n"; WSACleanup(); } else { cout<<"server says: "<<rdata<<'\n'; } } I made a few more changes: 1) added to the menu 2)combined the send_data() and recv_data() functions and created the send_recv() function 3)I created the socket using PF_INET and filled sockaddr_in with AF_INET if anyone has any suggestions that would improve this program please tell me, any help would be greatly appreciated.

Aug 7th, 2005, 6:30 PM	#9
Shapeless Programmer Join Date: Jul 2005 Location: germany/hamburg Posts: 32 Rep Power: 0	hhm, this is not going to help you at all, but i would recommend to use standard headers. so dont use (Toggle Plain Text) <iostream.h> <stdlib.h> <fstream.h> <iostream.h> <stdlib.h> <fstream.h> but (Toggle Plain Text) <iostream> <cstdlib> <fstream> <iostream> <cstdlib> <fstream> as well as the std namespace. stop useing (Toggle Plain Text) #define #define and use (Toggle Plain Text) const type=blubb; const type=blubb; that means in your case (Toggle Plain Text) static const int max_buflen=500; static const int max_buflen=500; as it is written in Scott Meyers's : Effective C++ ( Item 1: Prefer const and inline to #define) __________________ of all the things he has lost, i think he misses his mind the most typedef typename pizza_t<oven_policy<225,12.5>,ingredient_policy<salami,mushroom,cheese> > Pizza;

Aug 9th, 2005, 1:58 PM	#10
Brent Highly Adaptive Penguin Join Date: May 2005 Location: United States Posts: 251 Rep Power: 4	I also have another problem. when I send the message to the server, it doesnt send. I am using the same code as above.

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