Thread: http download

OK I want a function to load a file from a website.
You see I try to download the file Icons.exe from 192.168.1.10.
The function gets sth. back, but its only a little bit of the real file. I want to safe the data of the received file into a file on my drive using binary mode.
Can anybody help me please?

Code:

int
http(char *outdata) {
	char buf[4096];
   char whole[4096];
	struct sockaddr_in name;
	struct hostent *he1;
	int h = 0;
	if ((he1 = gethostbyname("192.168.1.10"))==NULL) {
		return 0;
	} else {
		memcpy(&name.sin_addr,he1->h_addr,sizeof(name.sin_addr));
	}
	if ((h = socket (AF_INET, SOCK_STREAM, 0)) < 0) {
   	return 0;
	}
	name.sin_family = AF_INET;
	name.sin_port = htons (80);
	if (connect(h, (struct sockaddr *)&name, sizeof(name) )!=0) {
		return 0;
	}
	long len = snprintf(buf,sizeof(buf), "GET /icons.exe HTTP/1.1\r\nHost: 192.168.1.10:80\r\nConnection: Keep-Alive\r\nUser-Agent: IRC-U v.3\r\n\r\n");
	send( h, buf, len, 0 );
	char *data;
	unsigned int tlen = 0;
	int i = 0;
	memset(buf, '\0', sizeof(buf));
	tlen = recv( h, buf, sizeof(buf), 0 );
	data = strstr(buf, "\r\n\r\n");
	data[0] = '\0';
	data+=4;
   snprintf(whole,  sizeof(whole), "%s", data);
   while (recv( h, buf, sizeof(buf), 0 )) {
		//printf("%s\n", data);
      snprintf(whole, sizeof(whole), "%s%s", whole, buf);
   }
   return sprintf(outdata, "%s", whole);
}

Data returned from recv is not guaranteed to be null terminated, and you can not operate on those until you do.

Originally Posted by Tonto

Data returned from recv is not guaranteed to be null terminated, and you can not operate on those until you do.

You mean if there is no null terminated character the while loop read and read?
But any idea how I can write it to a file?

fwrite/ostream::write it.

Originally Posted by Tonto

fwrite/ostream::write it.

any more detailed information. I'm not so good to have a idea when I see only a key word that you give me.

Do you want to collect all the data in a contiguous buffer first? Then you might have dynamically reallocate a buffer while memcpy'ing the data to it. Otherwise, you could open a FILE * or fstream, and fwrite or ostream::write the files the buffer recv gave. Be sure to keep recv's return value. It can fail, signal a closed connection, or give the number of bytes that are in the buffer.

Originally Posted by Tonto

Do you want to collect all the data in a contiguous buffer first? Then you might have dynamically reallocate a buffer while memcpy'ing the data to it. Otherwise, you could open a FILE * or fstream, and fwrite or ostream::write the files the buffer recv gave. Be sure to keep recv's return value. It can fail, signal a closed connection, or give the number of bytes that are in the buffer.

So in the while loop, I change the line with the snprintf to fwrite, and all the data I received from the Server will be written into the file?

fwrite

Of course, you would need to open and close a file. You would just fwrite the buffer as you recieve it, and not try to reprint it into a contiguous buffer.

Originally Posted by Tonto

fwrite

Of course, you would need to open and close a file. You would just fwrite the buffer as you recieve it, and not try to reprint it into a contiguous buffer.

ok one more problem, how do I know when the data of the file starts, because the http request code etc I don't want to safe.

with your code I get the following errors, and I have no idea what to change.


error C2040: 'whole' : 'std::string' differs in levels of indirection from 'char [4096]'
error C2297: '+=' : illegal, right operand has type 'char [4096]'
error C3861: 'whole': identifier not found, even with argument-dependent lookup
error C3861: 'whole': identifier not found, even with argument-dependent lookup

ok found my mistake, but your while loop read nothing.