coar 97/07/30 11:02:35
Modified: htdocs/manual/misc FAQ.html
Log:
Added item about the CGI/1.1 spec online locations, and some more
text about the FreeBSD/FD_SETSIZE stuff. (Marc has more to add
on that particular topic. but I'd already written this - so he
gets to correct/update my blither ;-)
PR: 931,938
Revision Changes Path
1.85 +100 -54 apache/htdocs/manual/misc/FAQ.html
Index: FAQ.html
===================================================================
RCS file: /export/home/cvs/apache/htdocs/manual/misc/FAQ.html,v
retrieving revision 1.84
retrieving revision 1.85
diff -u -r1.84 -r1.85
--- FAQ.html 1997/07/25 10:25:46 1.84
+++ FAQ.html 1997/07/30 18:02:33 1.85
@@ -15,7 +15,7 @@
<!--#include virtual="header.html" -->
<H1 ALIGN="CENTER">Apache Server Frequently Asked Questions</H1>
<P>
- $Revision: 1.84 $ ($Date: 1997/07/25 10:25:46 $)
+ $Revision: 1.85 $ ($Date: 1997/07/30 18:02:33 $)
</P>
<P>
The latest version of this FAQ is always available from the main
@@ -221,33 +221,36 @@
<LI><A HREF="#authauthoritative">Why does my authentification give
me a server error?</A>
<LI><A HREF="#auth-on-same-machine">Do I have to keep the (mSQL)
- authentification information on the same machine?</A>
+ authentification information on the same machine?</A>
</LI>
<LI><A HREF="#msql-slow">Why is my mSQL authentification terribly
slow?</A>
</LI>
<LI><A HREF="#rewrite-more-config">Where can I find mod_rewrite rulesets
- which already solve particular URL-related problems?</A>
+ which already solve particular URL-related problems?</A>
</LI>
<LI><A HREF="#rewrite-article">Where can I find any published information
about
- URL-manipulations and mod_rewrite?</A>
+ URL-manipulations and mod_rewrite?</A>
</LI>
<LI><A HREF="#rewrite-complexity">Why is mod_rewrite so difficult to learn
- and seems so complicated?</A>
+ and seems so complicated?</A>
</LI>
<LI><A HREF="#rewrite-dontwork">What can I do if my RewriteRules don't
work
- as expected?</A>
+ as expected?</A>
</LI>
- <LI><A HREF="#rewrite-prefixdocroot">Why are some of my URLs don't get
- prefixed with DocumentRoot when using mod_rewrite?</A>
+ <LI><A HREF="#rewrite-prefixdocroot">Why don't some of my URLs get
+ prefixed with DocumentRoot when using mod_rewrite?</A>
</LI>
<LI><A HREF="#rewrite-nocase">How can I make all my URLs case-insensitive
- with mod_rewrite?</A>
+ with mod_rewrite?</A>
</LI>
<LI><A HREF="#rewrite-virthost">Why are RewriteRules in my VirtualHost
- parts ignored?</A>
+ parts ignored?</A>
</LI>
<LI><A HREF="#rewrite-envwhitespace">How can I use strings with
whitespaces
- in RewriteRule's ENV flag?</A>
+ in RewriteRule's ENV flag?</A>
+ </LI>
+ <LI><A HREF="#cgi-spec">Where can I find the "CGI
+ specification"?</A>
</LI>
</OL>
</LI>
@@ -577,6 +580,7 @@
><SAMP>AddHandler</SAMP></A>
directive.
</P>
+ <P>
<OL>
<LI>In an appropriate section of your server configuration files, add
a line such as
@@ -597,10 +601,10 @@
HREF="../mod/core.html#options"
><SAMP>Options</SAMP></A>
declaration that includes the <SAMP>ExecCGI</SAMP> option.
- <P>
- </P>
</LI>
</OL>
+ </P>
+ <P>
In some situations it can be not conform to your local policy to actually
allow all files named "<SAMP>*.cgi</SAMP>" to be executable.
Perhaps all you want is to enable a particular file in a normal directory
to
@@ -611,16 +615,18 @@
><SAMP>mod_rewrite</SAMP></A>
and the following steps:
</P>
+ <P>
<OL>
<LI>Locally add to the corresponding <SAMP>.htaccess</SAMP> file a ruleset
similar to this one:
<P>
<DL>
- <DD><CODE>
- RewriteEngine on<br>
- RewriteBase /~foo/bar/<br>
- RewriteRule ^quux\.cgi$ - [T=application/x-httpd-cgi]<br>
- </CODE></DD>
+ <DD><CODE>RewriteEngine on
+ <BR>
+ RewriteBase /~foo/bar/
+ <BR>
+ RewriteRule ^quux\.cgi$ - [T=application/x-httpd-cgi]</CODE>
+ </DD>
</DL>
</P>
</LI>
@@ -628,12 +634,11 @@
<A
HREF="../mod/core.html#options"
><SAMP>Options</SAMP></A>
- declaration that includes the <SAMP>ExecCGI</SAMP> and
- <SAMP>FollowSymLinks</SAMP> option.
- <P>
- </P>
+ declaration that includes the <SAMP>ExecCGI</SAMP> and
+ <SAMP>FollowSymLinks</SAMP> option.
</LI>
</OL>
+ </P>
<HR>
</LI>
<LI><A NAME="premature-script-headers">
@@ -912,24 +917,25 @@
HREF="perf.html"
>performance hints</A>
page. There is a specific note for
- <a href="#freebsd-setsize">FreeBSD</a> below.
+ <A HREF="#freebsd-setsize">FreeBSD</A> below.
</LI>
<LI>"Don't do that" - try to run with fewer virtual hosts
</LI>
<LI>Spread your operation across multiple server processes (using
- <A
- HREF="../mod/core.html#listen"
- ><SAMP>Listen</SAMP></A>
- for example, but see the first point) and/or ports.
+ <A
+ HREF="../mod/core.html#listen"
+ ><SAMP>Listen</SAMP></A>
+ for example, but see the first point) and/or ports.
</LI>
</OL>
<P>
Since this is an operating-system limitation, there's not much else
available in the way of solutions.
+ </P>
<P>
As of 1.2.1 we have made attempts to work around various limitations
involving running with many descriptors.
- <a href="descriptors.html">More information is available.</a>
+ <A HREF="descriptors.html">More information is available.</A>
</P>
<HR>
</LI>
@@ -938,16 +944,32 @@
<STRONG>Can I increase <SAMP>FD_SETSIZE</SAMP> on FreeBSD?</STRONG>
</A>
<P>
- On FreeBSD 2.2 and older <SAMP>FD_SETSIZE</SAMP>, which limits the
- number of open
- files on the system, is limited to 256. This can restrict the number of
- virtual hosts you can use; especially if they all use different log
- files. Increasing this limit (and recompiling Apache) is not enough,
+ On versions of FreeBSD older than 2.2 <SAMP>FD_SETSIZE</SAMP>, which
+ limits the number of open files on the system, is controlled by a
+ kernel option and is limited to 256. You can set this value using a
+ line such as the following in your kernel configuration file:
+ </P>
+ <DL>
+ <DD><CODE>options FD_SETSIZE <EM>nnn</EM></CODE>
+ </DD>
+ </DL>
+ <P>
+ This can restrict the number of
+ virtual hosts you can use, especially if they all use different log
+ files. Increasing this limit (and recompiling Apache) is not enough,
as it is on some platforms (such as Solaris), as you also will have
to recompile <SAMP>libc</SAMP> with the changed setting.
</P>
<P>
- On FreeBSD 3.0 the default is 1024, so the problem is lessened.
+ With FreeBSD 2.2 and later, you <EM>can</EM> increase the setting of
+ <SAMP>FD_SETSIZE</SAMP> at Apache compilation time by adding
+ "<SAMP>-DFD_SETSIZE=<EM>nnn</EM></SAMP>" to the
+ <SAMP>EXTRA_CFLAGS</SAMP> line in your <SAMP>Configuration</SAMP>
+ file.
+ </P>
+ <P>
+ On FreeBSD 3.0 the default is 1024, so the problem is lessened still
+ more, and may not require any intervention at all.
</P>
<HR>
</LI>
@@ -1639,9 +1661,9 @@
<HR>
</LI>
<LI><A NAME="remote-user-var">
- <STRONG>Why is the environment variable
- <SAMP>REMOTE_USER</SAMP> not set?</STRONG>
- </A>
+ <STRONG>Why is the environment variable
+ <SAMP>REMOTE_USER</SAMP> not set?</STRONG>
+ </A>
<P>
This variable is set and thus available in SSI or CGI scripts <STRONG>if
and
only if</STRONG> the requested document was protected by access
@@ -1847,8 +1869,8 @@
<HR>
</LI>
<LI><A NAME="rewrite-more-config">
- <STRONG>Where can I find mod_rewrite rulesets which already solve
- particular URL-related problems?</STRONG>
+ <STRONG>Where can I find mod_rewrite rulesets which already solve
+ particular URL-related problems?</STRONG>
</A>
<P>
There is a collection of
@@ -1872,8 +1894,8 @@
<HR>
</LI>
<LI><A NAME="rewrite-article">
- <STRONG>Where can I find any published information about
URL-manipulations and
- mod_rewrite?</STRONG>
+ <STRONG>Where can I find any published information about
URL-manipulations and
+ mod_rewrite?</STRONG>
</A>
<P>
There is an article from
@@ -1898,8 +1920,8 @@
<HR>
</LI>
<LI><A NAME="rewrite-complexity">
- <STRONG>Why is mod_rewrite so difficult to learn and seems so
- complicated?</STRONG>
+ <STRONG>Why is mod_rewrite so difficult to learn and seems so
+ complicated?</STRONG>
</A>
<P>
Hmmm... there are a lot of reasons. First, mod_rewrite itself is a powerful
@@ -1924,8 +1946,8 @@
<HR>
</LI>
<LI><A NAME="rewrite-dontwork">
- <STRONG>What can I do if my RewriteRules don't work as expected?
- </STRONG>
+ <STRONG>What can I do if my RewriteRules don't work as expected?
+ </STRONG>
</A>
<P>
Use "<SAMP>RewriteLog somefile</SAMP>" and
@@ -1935,9 +1957,8 @@
</P>
<HR>
</LI>
- <LI><A NAME="rewrite-prefixdocroot">
- <STRONG>Why are some of my URLs don't get prefixed with DocumentRoot
- when using mod_rewrite?</STRONG>
+ <LI><A NAME="rewrite-prefixdocroot"><STRONG>Why don't some of my URLs
+ get prefixed with DocumentRoot when using mod_rewrite?</STRONG>
</A>
<P>
If the rule starts with <SAMP>/somedir/...</SAMP> make sure that really no
@@ -1951,8 +1972,8 @@
<HR>
</LI>
<LI><A NAME="rewrite-nocase">
- <STRONG>How can I make all my URLs case-insensitive with mod_rewrite?
- </STRONG>
+ <STRONG>How can I make all my URLs case-insensitive with
mod_rewrite?
+ </STRONG>
</A>
<P>
You can't! The reason is: First, case translations for arbitrary length
URLs
@@ -1971,8 +1992,8 @@
<HR>
</LI>
<LI><A NAME="rewrite-virthost">
- <STRONG> Why are RewriteRules in my VirtualHost parts ignored?
- </STRONG>
+ <STRONG> Why are RewriteRules in my VirtualHost parts ignored?
+ </STRONG>
</A>
<P>
Because you have to enable the engine for every virtual host explicitly due
@@ -1982,8 +2003,8 @@
<HR>
</LI>
<LI><A NAME="rewrite-envwhitespace">
- <STRONG> How can I use strings with whitespaces in RewriteRule's ENV
- flag?</STRONG>
+ <STRONG> How can I use strings with whitespaces in RewriteRule's
ENV
+ flag?</STRONG>
</A>
<P>
There is only one ugly solution: You have to surround the complete flag
@@ -1991,6 +2012,31 @@
to quote here is not the argument to the E-flag, it is the argument of the
Apache config file parser, i.e. the third argument of the RewriteRule here.
So you have to write <SAMP>"[E=any text with whitespaces]"</SAMP>.
+ </P>
+ <HR>
+ </LI>
+ <LI><A NAME="cgi-spec"><STRONG>Where can I find the "CGI
+ specification"?</STRONG></A>
+ <P>
+ The Common Gateway Interface (CGI) specification currently lives in at
+ least two versions:
+ </P>
+ <P>
+ <OL>
+ <LI>At the original NCSA site
+ <<A
+ HREF="http://hoohoo.ncsa.uiuc.edu/cgi/interface.html";
+ ><SAMP>http://hoohoo.ncsa.uiuc.edu/cgi/interface.html</SAMP></A>>.
+ This version hasn't been updated since 1995, and there have been
+ some efforts to update it and replace it with
+ </LI>
+ <LI>The most current version, which is struggling to become an
+ Internet RFC, found at
+ <<A
+ HREF="http://www.ast.cam.ac.uk/~drtr/cgi-spec.html";
+ ><SAMP>http://www.ast.cam.ac.uk/~drtr/cgi-spec.html</SAMP></A>>.
+ </LI>
+ </OL>
</P>
<HR>
</LI>
