//Author: Xukai Zou, 
//used for students' programming assignment in network course.
//gcc -lsocket -lnsl http_client.c 
//a.out www.cs.iupui.edu /index.html

#include <stdio.h>
#include <netdb.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
/*#include <sys/stat.h>
#include <fcntl.h>
#include <limits.h>
#include <arpa/inet.h>
#include <string.h>    */
int read_data(int s,     /* connected socket */
              char *buf, /* pointer to the buffer */
              int n      /* number of characters (bytes) we want */
             )
{ int bcount; /* counts bytes read */
  int br;     /* bytes read this pass */

  bcount= 0;
  br= 0;
  while (bcount < n) {             /* loop until full buffer */
    if ((br= read(s,buf,n-bcount)) > 0) {
      bcount += br;                /* increment byte counter */
      buf += br;                   /* move buffer ptr for next read */
    }
    else if (br < 0)               /* signal an error to the caller */
      return(-1);
  }
  return(bcount);
}

int main(int argc, char *argv[])
{
	struct sockaddr_in servAddr;
	char receiveBuffer[5000],req[200];
	int sockID;
	struct hostent *hostp;
 	if(argc!=3){
		printf("Usage: %s host-name file_path_name\n",argv[0]);
		return (1);
	}
	//open the socket
	if((sockID=socket(AF_INET,SOCK_STREAM,0))<0)
	{
		printf("Error to open socket!!");
		return (0);
	}
  
		//set the server structure
		bzero((char *)&servAddr,sizeof(servAddr));
		if((hostp=gethostbyname(argv[1]))==0){ //get host IP by host name
			printf("host %s not found!\n",argv[1]);
			return 1;
		}
		//the IP address is in hostP, copy to servAddr
		servAddr.sin_family=AF_INET;
		servAddr.sin_port=htons(80);  //http port 
		//bcopy(&servAddr.sin_addr.s_addr,hostp->sin_addr,sizeof(hostp->length));
		memcpy((void *)&servAddr.sin_addr,hostp->h_addr,hostp->h_length);
  		//connect the host
		printf("Connectionning !!\n");

		if(connect(sockID,(struct sockaddr *)&servAddr,sizeof(servAddr))<0)
		{
			printf("Fail to connect to host %s\n",argv[1]);
			return 1;
		}
		printf("Connection successful!!\n");
		//transfer data
		//form the request string
		sprintf(req,"GET %s \r\n",argv[2]);
		printf("Sending the request=%s \n",req);
		write(sockID,req,sizeof(req)); //send request
		//read 1000 chars, can modify to read entire content 
		printf("Reading the data \n");
		read_data(sockID,receiveBuffer,1000);
		printf("%s",receiveBuffer);

}