Commit 4af97751 authored by Ken Coar's avatar Ken Coar
Browse files

Clean up "premature end of headers" FAQ and add additional 

	(and more common) cause description.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@78298 13f79535-47bb-0310-9956-ffa450edef68
parent 46442648

docs/manual/misc/FAQ.html

+32 −11
Changes for docs/manual/misc/FAQ.html: 32 added lines, 11 removed lines.
Original line number Diff line number Diff line
@@ -15,7 +15,7 @@ 
  <!--#include virtual="header.html" -->

  <H1 ALIGN="CENTER">Apache Server Frequently Asked Questions</H1>

  <P>

  $Revision: 1.70 $ ($Date: 1997/06/12 11:29:11 $)

  $Revision: 1.71 $ ($Date: 1997/06/12 15:24:00 $)

  </P>

  <P>

  The latest version of this FAQ is always available from the main
@@ -569,17 +569,36 @@ 
  <P>

  It means just what it says: the server was expecting a complete set of

  HTTP headers (one or more followed by a blank line), and didn't get

  them.  The most common cause of this (aside from people not

  outputting the required headers at all) a result of an interaction

  with perl's output buffering.  To make perl flush its buffers 

  after each output statement, insert the following statements before your

  first <CODE>print</CODE> or <CODE>write</CODE> statement:

  them.

  </P>

  <P>

  The most common cause of this problem is the script dying before

  sending the complete set of headers, or possibly any at all, to the

  server.  To see if this is the case, try running the script standalone

  from an interactive session, rather than as a script under the server.

  If you get error messages, this is almost certainly the cause of the

  &quot;premature end of script headers&quot; message.

  </P>

  <P>

  The second most common cause of this (aside from people not

  outputting the required headers at all) is a result of an interaction

  with Perl's output buffering.  To make Perl flush its buffers 

  after each output statement, insert the following statements around

  the <CODE>print</CODE> or <CODE>write</CODE> statements that send your

  HTTP headers:

  </P>

  <P>

  <DL>

   <DD><CODE>$cfh = select (STDOUT);<BR>

    $| = 1;<BR>

    select ($cfh);</CODE>

   <DD><CODE>{<BR>

    &nbsp;local ($oldbar) = $|;<BR>

    &nbsp;$cfh = select (STDOUT);<BR>

    &nbsp;$| = 1;<BR>

    &nbsp;#<BR>

    &nbsp;# print your HTTP headers here<BR>

    &nbsp;#<BR>

    &nbsp;$| = $oldbar;<BR>

    &nbsp;select ($cfh);<BR>

    }</CODE>

   </DD>

  </DL>

  </P>
@@ -588,8 +607,10 @@ 
  programs from your script that send output to stdout, or if there will

  be a long delay between the time the headers are sent and the actual

  content starts being emitted.  To maximise performance, you should

  turn buffering back <EM>on</EM> (with <CODE>$| = 0</CODE> or the

  equivalent) after the statements that send the headers.

  turn buffer-flushing back <EM>off</EM> (with <CODE>$| = 0</CODE> or the

  equivalent) after the statements that send the headers, as displayed

  above.

  </P>

  <P>

  If your script isn't written in Perl, do the equivalent thing for

  whatever language you <EM>are</EM> using (<EM>e.g.</EM>, for C, call