/*
 * ISA 563, Spring 2011
 * Copyleft by Muhammad Abdulla
 */

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

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>

/*
 * www-client.c -- demonstrates client-side socket operations
 */

#define HTTPPORT 80

int main ( int argc, char *argv[] )
{
   int sock;
   int retval;
   struct sockaddr_in sin ;
   struct hostent *hen ;
   FILE *fp;
   char line[1024];

   char *host = "www.gmu.edu";
   char *uri  = "/";

   if ( argc > 1 ) {
      host = argv[1];
   }

   if ( argc > 2 ) {
      uri = argv[2];
   }

   // create a TCP socket
   sock = socket ( AF_INET, SOCK_STREAM, 0 ) ; 

   if ( sock < 0 ) {
      fprintf(stderr, "Could not create a socket.\n"); 
      exit(1);
   }
 
   memset ( &sin, 0, sizeof(sin) ) ;

   sin.sin_family = AF_INET ;
   sin.sin_port = htons ( (short) HTTPPORT ) ;

   if ( hen = gethostbyname(host) ) { // first try alpha-numerical address
      memcpy ( &sin.sin_addr, hen->h_addr, hen->h_length ) ;
   } else { // doesn't seem to be alpha-numerical, try dotted decimal
      if ( inet_pton ( AF_INET, host, &sin.sin_addr ) < 1 ) {
         fprintf(stderr, "Invalid hostname: %s.\n", host); 
         exit(1);
      }
   }

   retval = connect ( sock, (struct sockaddr *) &sin, sizeof(sin) ) ;

   if ( retval < 0 ) {
      fprintf(stderr, "Could not connect to host %s.\n", host); 
      return -1;
   }

   fp = fdopen(sock, "r+");

   if ( fp == NULL ) {
      fprintf(stderr, "fdopen error.\n"); 
      return -1;
   }

   fprintf(fp, "GET %s\n", uri);

   while ( fgets(line, sizeof(line), fp) != NULL ) {
      fprintf(stdout, "%s", line);
   }
}