tejasri-v/#Lab6part2.txt Secret

## #Lab6part2.txt
Part 2: Web page downloader
---------------------------

There is a very useful program called "wget".  It's a command line
tool that you can use to download a web page like this:

    wget http://www.gnu.org/software/make/manual/make.html

which will download the make manual page, make.html, and save it in
the current directory.  wget can do much more (downloading a whole web
site, for example); see man wget for more info.

Your job is to write a limited version of wget, which we will call
http-client.c, that can download a single file.  You use it like this:

    ./http-client www.gnu.org 80 /software/make/manual/make.html

So you give the components of the URL separately in the command line:
the host, the port number, and the file path.  The program will
download the given file and save it in the current directory.  So
in the case above, it should produce make.html in the current
directory.  It should overwrite an existing file.

Hints:

- The program should open a socket connection to the host and port
  number specified in the command line, and then request the given
  file using HTTP 1.0 protocol.  (See
  http://www.jmarshall.com/easy/http/ for HTTP 1.0 protocol.) An HTTP
  GET request looks like this:

      GET /path/file.html HTTP/1.0
      [zero or more headers ...]
      [a blank line]

- Include the following header in your request:

      Host: the.host.name.you.are.connecting.to:<port_number>

  Some web sites require it.

- Use "\r\n" rather than "\n" as newline when you send your request.
  It's required by the HTTP protocol.

- Then the program reads the response from the web server which looks
  like this:

      HTTP/1.0 200 OK
      Date: Fri, 31 Dec 1999 23:59:59 GMT
      Content-Type: text/html
      Content-Length: 1354

      <html>
      <body>
      <h1>Happy New Millennium!</h1>
      (more file contents)
        .
        .
        .
      </body>
      </html>

  Just like in part 1, you can use fdopen() to wrap the socket with a
  FILE*, which will make reading the lines much easier.

- The "200" in the 1st line indicates that the request was successful.
  If it's not 200, the program should print the 1st line and exit.

- After the 1st line, a bunch of headers will come, then comes a blank
  line, and then the actual file content starts.  Your program should
  skip over all headers and just receive the file content.

- Note that the program should be able to download any type of file, not
  just HTML files.

- The server will terminate the socket connection when it's done
  sending the file.

- You will need to pick out the file name part of a file path
  (make.html from /software/make/manual/make.html for example).  Check
  out strrchr().

- You will need to convert a host name into an IP address. Here is one way
  to convert a host name into an IP address in dotted-quad notation:

	struct hostent *he;
	char *serverName = argv[1];

	// get server ip from server name
	if ((he = gethostbyname(serverName)) == NULL) {
	    die("gethostbyname failed");
	}
	char *serverIP = inet_ntoa(*(struct in_addr *)he->h_addr);

  The man pages of the functions will tell you which header files need to be
  included.

--

Good luck!

## http-client.c
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <arpa/inet.h>

static void die(const char *s) { perror(s); exit(1); }

int main(int argc, char **argv)
{
	if (argc != 4){
                fprintf(stderr, "usage: %s <host> <port> <file-path>\n", argv[0]);
		exit(1);
	}

	struct hostent *he;
	char *serverName = argv[1];
	if ((he = gethostbyname(serverName)) == NULL)
		die("gethostbyname failed");

	char *serverIP = inet_ntoa(*(struct in_addr *)he->h_addr);

	unsigned short port = atoi(argv[2]);

	int sock;
	if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
		die("socket failed");

	struct sockaddr_in servaddr;
	memset(&servaddr, 0, sizeof(servaddr));
	servaddr.sin_family = AF_INET;
	servaddr.sin_addr.s_addr = inet_addr(serverIP);
	servaddr.sin_port = htons(port);

	if (connect(sock, (struct sockaddr *) &servaddr, sizeof(servaddr)) < 0)
		die("connect failed");

	char buf[1000];
	snprintf(buf, 1000, "GET %s HTTP/1.0\r\n", argv[3]);
	size_t len = strlen(buf);
	if(send(sock, buf, len, 0) != len)
		die("send failed");
	snprintf(buf, 1000, "Host: %s:%s\r\n", argv[1], argv[2]);
	len = strlen(buf);
	if(send(sock, buf, len, 0) != len)
                die("send failed");
	snprintf(buf, 1000, "\r\n");
	len = strlen(buf);
        if(send(sock, buf, len, 0) != len)
                die("send failed"); //not sure that this is the right way to print everything ->is it cheating to send three times


	FILE *response = fdopen(sock, "r");
	char a[1000];
	fgets(a, 1000, response);
//	printf("%s", a);
	if(a[9] == '2' && a[10] == '0' && a[11] == '0'){

		while(a[strlen(a)-1] == '\n' && a[strlen(a)-2] == '\r' && strlen(a) > 2){
			fgets(a, 1000, response);
		}
	//	fgets(a, 1000, response);
	//	if(strlen(a) != 2)
	//		printf("not past the header");

	//	fgets(a, 1000, response);
	//	printf("%s", a);


		FILE *fp;
        	char *name;
        	name = strrchr(argv[3], '/');
        	fp = fopen(name+1, "w");
		if(fp == NULL)
			die("fopen failed");


		char b[1000];
		while(fread(b, 1, 1, response) == 1){

			fwrite(b, 1, 1, fp);

		}

	}
	else{
		printf("%s", a);
		exit(1);
	}


}

## Makefile
CC = gcc
CXX = g++

CFLAGS = -g -Wall $(INCLUDES)
CXXFLAGS = -g -Wall $(INCLUDES)

.PHONY: default
default: http-client

.PHONY: clean
clean:
	rm -f *.o *~ a.out core http-client

.PHONY: all
all: clean default
	Part 2: Web page downloader
	---------------------------

	There is a very useful program called "wget". It's a command line
	tool that you can use to download a web page like this:

	wget http://www.gnu.org/software/make/manual/make.html

	which will download the make manual page, make.html, and save it in
	the current directory. wget can do much more (downloading a whole web
	site, for example); see man wget for more info.

	Your job is to write a limited version of wget, which we will call
	http-client.c, that can download a single file. You use it like this:

	./http-client www.gnu.org 80 /software/make/manual/make.html

	So you give the components of the URL separately in the command line:
	the host, the port number, and the file path. The program will
	download the given file and save it in the current directory. So
	in the case above, it should produce make.html in the current
	directory. It should overwrite an existing file.

	Hints:

	- The program should open a socket connection to the host and port
	number specified in the command line, and then request the given
	file using HTTP 1.0 protocol. (See
	http://www.jmarshall.com/easy/http/ for HTTP 1.0 protocol.) An HTTP
	GET request looks like this:

	GET /path/file.html HTTP/1.0
	[zero or more headers ...]
	[a blank line]

	- Include the following header in your request:

	Host: the.host.name.you.are.connecting.to:<port_number>

	Some web sites require it.

	- Use "\r\n" rather than "\n" as newline when you send your request.
	It's required by the HTTP protocol.

	- Then the program reads the response from the web server which looks
	like this:

	HTTP/1.0 200 OK
	Date: Fri, 31 Dec 1999 23:59:59 GMT
	Content-Type: text/html
	Content-Length: 1354

	<html>
	<body>
	<h1>Happy New Millennium!</h1>
	(more file contents)
	.
	.
	.
	</body>
	</html>

	Just like in part 1, you can use fdopen() to wrap the socket with a
	FILE*, which will make reading the lines much easier.

	- The "200" in the 1st line indicates that the request was successful.
	If it's not 200, the program should print the 1st line and exit.

	- After the 1st line, a bunch of headers will come, then comes a blank
	line, and then the actual file content starts. Your program should
	skip over all headers and just receive the file content.

	- Note that the program should be able to download any type of file, not
	just HTML files.

	- The server will terminate the socket connection when it's done
	sending the file.

	- You will need to pick out the file name part of a file path
	(make.html from /software/make/manual/make.html for example). Check
	out strrchr().

	- You will need to convert a host name into an IP address. Here is one way
	to convert a host name into an IP address in dotted-quad notation:

	struct hostent *he;
	char *serverName = argv[1];

	// get server ip from server name
	if ((he = gethostbyname(serverName)) == NULL) {
	die("gethostbyname failed");
	}
	char serverIP = inet_ntoa((struct in_addr *)he->h_addr);

	The man pages of the functions will tell you which header files need to be
	included.

	--

	Good luck!
	#include <ctype.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <assert.h>
	#include <unistd.h>
	#include <sys/wait.h>
	#include <sys/stat.h>
	#include <arpa/inet.h>
	#include <sys/types.h>
	#include <sys/socket.h>
	#include <netdb.h>
	#include <arpa/inet.h>

	static void die(const char *s) { perror(s); exit(1); }

	int main(int argc, char **argv)
	{
	if (argc != 4){
	fprintf(stderr, "usage: %s <host> <port> <file-path>\n", argv[0]);
	exit(1);
	}

	struct hostent *he;
	char *serverName = argv[1];
	if ((he = gethostbyname(serverName)) == NULL)
	die("gethostbyname failed");

	char serverIP = inet_ntoa((struct in_addr *)he->h_addr);

	unsigned short port = atoi(argv[2]);

	int sock;
	if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
	die("socket failed");

	struct sockaddr_in servaddr;
	memset(&servaddr, 0, sizeof(servaddr));
	servaddr.sin_family = AF_INET;
	servaddr.sin_addr.s_addr = inet_addr(serverIP);
	servaddr.sin_port = htons(port);

	if (connect(sock, (struct sockaddr *) &servaddr, sizeof(servaddr)) < 0)
	die("connect failed");

	char buf[1000];
	snprintf(buf, 1000, "GET %s HTTP/1.0\r\n", argv[3]);
	size_t len = strlen(buf);
	if(send(sock, buf, len, 0) != len)
	die("send failed");
	snprintf(buf, 1000, "Host: %s:%s\r\n", argv[1], argv[2]);
	len = strlen(buf);
	if(send(sock, buf, len, 0) != len)
	die("send failed");
	snprintf(buf, 1000, "\r\n");
	len = strlen(buf);
	if(send(sock, buf, len, 0) != len)
	die("send failed"); //not sure that this is the right way to print everything ->is it cheating to send three times



	FILE *response = fdopen(sock, "r");
	char a[1000];
	fgets(a, 1000, response);
	// printf("%s", a);
	if(a[9] == '2' && a[10] == '0' && a[11] == '0'){

	while(a[strlen(a)-1] == '\n' && a[strlen(a)-2] == '\r' && strlen(a) > 2){
	fgets(a, 1000, response);
	}
	// fgets(a, 1000, response);
	// if(strlen(a) != 2)
	// printf("not past the header");

	// fgets(a, 1000, response);
	// printf("%s", a);


	FILE *fp;
	char *name;
	name = strrchr(argv[3], '/');
	fp = fopen(name+1, "w");
	if(fp == NULL)
	die("fopen failed");


	char b[1000];
	while(fread(b, 1, 1, response) == 1){

	fwrite(b, 1, 1, fp);

	}

	}
	else{
	printf("%s", a);
	exit(1);
	}




	}
	CC = gcc
	CXX = g++

	CFLAGS = -g -Wall $(INCLUDES)
	CXXFLAGS = -g -Wall $(INCLUDES)

	.PHONY: default
	default: http-client

	.PHONY: clean
	clean:
	rm -f .o ~ a.out core http-client

	.PHONY: all
	all: clean default