Hello, I have a problem with a tcp program in c++, using bloodshed Dev c++ Compiler. I've been programming using .NET alot before but given up that because of the need of .NET Famework. This here i my code but I get a lot of Linker Errors. #include <stdlib.h> #include <stdio.h> #include <string.h> #include <winsock.h> void TCPecho(const char *, const char *); void errexit(const char *, ...); SOCKET connectTCP(const char *, const char *); #define LINELEN 128 #define WSVERS MAKEWORD(2, 0) ---------------- * main - TCP client for ECHO service ---------------- */ int main(int argc, char *argv[]) { char *host = "localhost"; /* host to use if none supplied */ char *service = "echo"; /* default service name */ WSADATA wsadata; switch (argc) { case 1: host = "localhost"; break; case 3: service = argv[2]; /* FALL THROUGH */ case 2: host = argv[1]; break; default: fprintf(stderr, "usage: TCPecho [host [port]]\n"); exit(1); } if (WSAStartup(WSVERS, &wsadata) != 0) errexit("WSAStartup failed\n"); TCPecho(host, service); WSACleanup(); exit(0); } ---------------- * TCPecho - send input to ECHO service on specified host and print reply ---------------- */ void TCPecho(const char *host, const char *service) { char buf[LINELEN+1]; /* buffer for one line of text */ SOCKET s; /* socket descriptor */ int cc, outchars, inchars; /* characters counts */ s = connectTCP(host, service); while (fgets(buf, sizeof(buf), stdin)) { buf[LINELEN] = '\0'; /* ensure line null-termination */ outchars = strlen(buf); (void) send(s, buf, outchars, 0); /* read it back */ for (inchars = 0; inchars < outchars; inchars += cc) { cc = recv(s, &buf[inchars], outchars-inchars, 0); if (cc == SOCKET_ERROR) errexit("socket recv failed: %d\n", GetLastError()); } fputs(buf, stdout); } closesocket(s); } Any Idea why? Or could anyone give me a link to a tutorial in c++ TCP/IP? Thanks Live the life as you know it / Wille

For a good, low-level but thorough tutorial using C, see Beej's Guide to Network Programming. In particular, section 1.5 tells you what DLLs you need to link. For an example of a well-designed C++ networking library, see the Boost Sockets Library.

You need to add the libws2_32.a library. That'll take care of everything except errexit() and connectTCP(); both of which you declare, but never define. Edit: Fixed the library name. That's what I get for going from memory, I suppose.

Razor, isn't libw2_32.a a Unix library, rather than Windows?