HttpHeader Request only part of an entity

[squidge]

Send a HEAD request to the server, it will reply with the same header (but no body) as if you sent GET. In this header, you will receive Content-length which will be the size of the file as long as you do not include a "Range" header in your HEAD request (else you'll get the size of your range, which isn't what you want).

Note that not all servers support this, in which case you will be transferring "blind" and will have to depend on a short read.

[nhs_0702]

Send a HEAD request to the server, it will reply with the same header (but no body) as if you sent GET. In this header, you will receive Content-length which will be the size of the file as long as you do not include a "Range" header in your HEAD request (else you'll get the size of your range, which isn't what you want).

Note that not all servers support this, in which case you will be transferring "blind" and will have to depend on a short read.

yes, I also think it will get by, but really I do not known write in QTcreator how to get respond Http header, I havent example by learn

[wysota]

Come on, man. Simply instead of a "get" request, make a "head" request.

[nhs_0702]

Come on, man. Simply instead of a "get" request, make a "head" request.

QFile qfFileHeader("Header.txt");
	if (!qfFileHeader.open(QIODevice::WriteOnly)) {
		QMessageBox::information(this, tr("HTTP"),tr("Unable to save the file %1: %2.").arg(qsFileName).arg(qfFileOut->errorString()));
		return;
	}
	QHttpRequestHeader qhrhHeaderRespond("HEAD", qbaUrlPath);
	qhrhHeaderRespond.setValue("Host", qsHost);
	qhHttpRespond->setHost(qsHost, qhconMode, quUrl.port() == -1 ? 0 : quUrl.port());
	if (!quUrl.userName().isEmpty())
		qhHttpRespond->setUser(quUrl.userName(), quUrl.password());
	qhHttpRespond->request(qhrhHeaderRespond, 0, &qfFileHeader);

QFile qfFileHeader("Header.txt");
	if (!qfFileHeader.open(QIODevice::WriteOnly)) {
		QMessageBox::information(this, tr("HTTP"),tr("Unable to save the file %1: %2.").arg(qsFileName).arg(qfFileOut->errorString()));
		return;
	}
	QHttpRequestHeader qhrhHeaderRespond("HEAD", qbaUrlPath);
	qhrhHeaderRespond.setValue("Host", qsHost);
	qhHttpRespond->setHost(qsHost, qhconMode, quUrl.port() == -1 ? 0 : quUrl.port());
	if (!quUrl.userName().isEmpty())
		qhHttpRespond->setUser(quUrl.userName(), quUrl.password());
	qhHttpRespond->request(qhrhHeaderRespond, 0, &qfFileHeader);

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it dont get in File Header.txt

[wysota]

I think you misunderstand what a "head" request is.

http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html

[nhs_0702]

I think you misunderstand what a "head" request is.

http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html

must i get content-length in Funcition void HttpWindow::readResponseHeader(const QHttpResponseHeader &responseHeader) by funciton QString s =responseHeader.toString(); ?
but i get mis information

Ex:

+ s "HTTP/1.1 200 OK
Date: Sat, 24 Apr 2010 00:41:00 GMT
Server: Apache/2.0.63 (Unix) mod_ssl/2.0.63 OpenSSL/0.9.8e-fips-rhel5 mod_auth_passthrough/2.1 mod_bwlimited/1.4 PHP/5.2.8
Last-Modified: Sat, QString

[wysota]

must i get content-length in Funcition void HttpWindow::readResponseHeader(const QHttpResponseHeader &responseHeader) by funciton QString s =responseHeader.toString(); ?
but i get mis information

I have no idea what you mean. Please rephrase the question.

[nhs_0702]

I have no idea what you mean. Please rephrase the question.

thank you,i was get file size,thank you again

[squidge]

Not every server supports Content-length. You should use it if its there, but you can't depend on it being there. This is why web browsers sometimes say "Downloaded 130KB of unknown" for example.