/******************************************************************************
            webclient.c - Simple web client using Winsock 

  This program demonstrates the use of the Windows Sockets API for a simple 
  web client application.  The user interface is via a MS Dos window.

  This program has been compiled and tested under Microsoft Visual C++ 6.0.

  Copyright 2005 by Ziping Liu
  Prepared for CS480, Southeast Missouri State University

******************************************************************************/
/*-----------------------------------------------------------------------
 *
 * Program: webclient
 * Purpose: fetch page from webserver and dump to stdout with headers
 * Usage:   webclient <compname> <path> [portnum]
 * Note:    <compname> can be either a computer name, like localhost, xx.cs.semo.edu
 *          or an IP address, like 150.168.0.1
 *-----------------------------------------------------------------------
 */
#include <winsock2.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <fcntl.h>

#define DEFAULT_PROTO SOCK_STREAM 
#define BUFFSIZE	256
#define STDIN_FILENO  0
#define STDOUT_FILENO 1

int main(int argc, char *argv[])
{
	int retval;                         /* status return value */
	unsigned int addr;
	int socket_type = DEFAULT_PROTO;    /* use TCP protocol */
	struct sockaddr_in server;          /* socket address and port */
	struct hostent *hp;                 /* ptr to host info struct */
	WSADATA wsaData;                    /* Windows Sockets API data */
	SOCKET  conn_socket;                /* socket descriptor */
	char BufferOut[BUFFSIZE];            /* buffer to hold out sentence */
	char BufferIn[BUFFSIZE];             /* buffer to hold in sentence */
    int bufcnt;                         /* no. of chars in buffer */                            

	if (argc < 3 || argc > 4) {
		fprintf(stderr, "%s%s%s", "usage: ", argv[0], 
			       " <compname> <path> [appnum]\n");
		exit(1);
	}

	/*------------------------------------------------------------------------*/
    /*                   Start up the Windows Sockets API.                    */
	/*------------------------------------------------------------------------*/
    printf( "Client: Starting WinSock API...\n" );
	if (WSAStartup(0x202,&wsaData) == SOCKET_ERROR) {
		fprintf(stderr,"WSAStartup failed with error %d\n",WSAGetLastError());
		WSACleanup();
		return -1;
	}

	/*------------------------------------------------------------------------*/
	/* Attempt to detect if we should call gethostbyname() or gethostbyaddr() */
	/*------------------------------------------------------------------------*/
	/* call isalpha() function to determine the first character of the server name 
	   is a character or a numeric number */
	if (isalpha(*argv[1])) {   /* server address is a name */
		hp = gethostbyname(argv[1]);
	}
	else  { /* Convert nnn.nnn address to a usable one */
		addr = inet_addr(argv[1]);
		hp = gethostbyaddr((char *)&addr,4,AF_INET);
	}
	if (hp == NULL ) {
		fprintf(stderr,"Client: Cannot resolve address [%s]: Error %d\n",
			argv[1], WSAGetLastError());
		WSACleanup();
		exit(1);
	}

	/*------------------------------------------------------------------------*/
	/*      Copy the resolved information into the sockaddr_in structure      */
	/*------------------------------------------------------------------------*/
	memset(&server,0,sizeof(server));
	memcpy(&(server.sin_addr),hp->h_addr,hp->h_length);
	server.sin_family = hp->h_addrtype;
	server.sin_port = htons(atoi(argv[3]));


    /*-----------------------------------------------------------------------*/
    /*                  Create the socket                                    */
    /*-----------------------------------------------------------------------*/
	conn_socket = socket(AF_INET,socket_type,0); 
	if (conn_socket <0 ) {
		fprintf(stderr,"Client: Error Opening socket: Error %d\n",
			WSAGetLastError());
		WSACleanup();
		return -1;
	}

    /*----------------------------------------------------------------------*/
    /*          Connect and bind the socket                                 */
    /*----------------------------------------------------------------------*/
    printf("Client connecting to: %s\n",hp->h_name);
	if (connect(conn_socket,(struct sockaddr*)&server,sizeof(server))
		== SOCKET_ERROR) {
		fprintf(stderr,"connect() failed: %d\n",WSAGetLastError());
		WSACleanup();
		return -1;
	}

	/* send an HTTP/1.0 request to the webserver */
	bufcnt = sprintf(BufferOut, "GET %s HTTP/1.0\r\n\r\n", argv[2]);
	send(conn_socket, BufferOut, bufcnt, 0);

	/* dump all data received from the server to stdout */
	while((retval = recv(conn_socket, BufferOut, BUFFSIZE, 0)) > 0)
		fwrite(BufferOut, sizeof(char), retval, stdout);

    /*---------------------------------------------------------------------*/
    /*					Close connection and Clean up                      */
    /*---------------------------------------------------------------------*/
	closesocket(conn_socket);
	WSACleanup();

	return 0;
}