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'\" $Header: /cvsroot/aolserver/aolserver/doc/Ns_ConnQueueHeaders.3,v 1.1 2006/04/19 17:37:30 jgdavidson Exp $
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.TH Ns_ConnQueueHeaders 3aolserver 4.0 AOLserver "AOLserver Library Procedures"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
Ns_ConnQueueHeaders, Ns_ConnFlushHeaders \- Routines to construct send HTTP response headers
.SH SYNOPSIS
.nf
\fB#include "ns.h"\fR
.sp
void
\fBNs_ConnFlushHeaders\fR(\fIconn, status\fR)
.sp
void
\fBNs_ConnQueueHeaders\fR(\fIconn, status\fR)
.SH ARGUMENTS
.AS Ns_Conn conn in
.AP Ns_Conn conn in
Pointer to open connection.
.AP int status in
HTTP response status.
.BE

.SH DESCRIPTION
.PP
These function format headers pending in the \fIoutputheaders\fR
Ns_Set of the given \fIconn\fR Ns_Conn structure to be sent to the
client.  The headers data along with a preceeding HTTP response
line with the given \fIstatus\fR code (e.g., "HTTP/1.1 200 OK") is
formatted as a single string with \fI\r\n\fR separators between
header \fIkey: value\fR pairs and a trailing \fI\r\n\fR to indicate
end of headers.

.TP
int \fBNs_ConnFlushHeaders\fR(\fIconn\fR)
This routine constructs the headers and then attempts to send them
immediately to the client.  The result is either NS_OK if the content
was sent, NS_ERROR otherwise.

.TP
void \fBNs_ConnQueueHeaders\fR(\fIconn\fR)
This routine constructs the headers as with \fBNs_ConnFlushHeaders\fR
but does not send the data to the client.  Instead, the resulting
headers string is stored in an internal buffer to be sent later on
the first call to \fBNs_ConnSend\fR.  Delaying the flush of the
content helps increase performance by providing the opportunity to
combine the headers and content responses into a single system call.

.PP
Note that higher level routines which generate complete responses
such as the \fBNs_ConnReturn\fR routines or \fBNs_ConnFlush\fR call
\fBNs_ConnQueueHeaders\fR automatically as needed.  Only custom
code which constructs headers manually and sends content directly
must include a call to \fBNs_ConnQueueHeaders\fR or
\fBNs_ConnFlushHeaders\fR before generating the output content.

.SH EXAMPLES
The following example demonstrates a simple response.  In this case,
the headers are queued and sent with the small "hello" message on
the call to \fBNs_ConnPuts\fR which internally calls \fBNs_ConnSend\fR:

.CS
	Ns_ConnSetRequiredHeaders(conn, "text/plain", 5);
	Ns_ConnQueueHeaders(conn, 200);
	Ns_ConnPuts(conn, "hello");
.CE

.SH "SEE ALSO"
Ns_ConnSetHeaders(3), Ns_ConnSend(3)

.SH KEYWORDS
connection, headers