/* consock.cpp - connectsock */#include <stdlib.h>#include <stdio.h>#include <string.h>#include <winsock.h>#ifndef	INADDR_NONE#define	INADDR_NONE	0xffffffff#endif	/* INADDR_NONE */void	errexit(const char *, ...);/*------------------------------------------------------------------------ * connectsock - allocate & connect a socket using TCP or UDP *------------------------------------------------------------------------ */SOCKETconnectsock(const char *host, const char *service, const char *transport ){	struct hostent	*phe;	/* pointer to host information entry	*/	struct servent	*pse;	/* pointer to service information entry	*/	struct protoent *ppe;	/* pointer to protocol information entry*/	struct sockaddr_in sin;	/* an Internet endpoint address		*/	int	s, type;	/* socket descriptor and socket type	*/	memset(&sin, 0, sizeof(sin));	sin.sin_family = AF_INET;    /* Map service name to port number */	if ( pse = getservbyname(service, transport) )		sin.sin_port = pse->s_port;	else if ( (sin.sin_port = htons((u_short)atoi(service))) == 0 )		errexit("can't get \"%s\" service entry\n", service);    /* Map host name to IP address, allowing for dotted decimal */	if ( phe = gethostbyname(host) )		memcpy(&sin.sin_addr, phe->h_addr, phe->h_length);	else if ( (sin.sin_addr.s_addr = inet_addr(host)) == INADDR_NONE)		errexit("can't get \"%s\" host entry\n", host);    /* Map protocol name to protocol number */	if ( (ppe = getprotobyname(transport)) == 0)		errexit("can't get \"%s\" protocol entry\n", transport);    /* Use protocol to choose a socket type */	if (strcmp(transport, "udp") == 0)		type = SOCK_DGRAM;	else		type = SOCK_STREAM;    /* Allocate a socket */	s = socket(PF_INET, type, ppe->p_proto);	if (s == INVALID_SOCKET)		errexit("can't create socket: %d\n", GetLastError());    /* Connect the socket */	if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) ==	    SOCKET_ERROR)		errexit("can't connect to %s.%s: %d\n", host, service,			GetLastError());	return s;}