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| author | paul <paul@unknown> | 1996-11-18 20:51:08 +0100 |
|---|---|---|
| committer | paul <paul@unknown> | 1996-11-18 20:51:08 +0100 |
| commit | 2ada5933c85b2ca45770c2df27e2d292667f36c4 (patch) | |
| tree | 53c64bebbb2a1da979c0ac496b2db09ba38c495d /docs/manual/custom-error.html | |
| parent | Added a test index.html file and an image to a default htdocs directory to (diff) | |
| download | apache2-2ada5933c85b2ca45770c2df27e2d292667f36c4.tar.xz apache2-2ada5933c85b2ca45770c2df27e2d292667f36c4.zip | |
New manual setup. This is the current docs for all versions of the
server merged into a single manual.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@76987 13f79535-47bb-0310-9956-ffa450edef68
Diffstat (limited to 'docs/manual/custom-error.html')
| -rw-r--r-- | docs/manual/custom-error.html | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/docs/manual/custom-error.html b/docs/manual/custom-error.html new file mode 100644 index 0000000000..31c955a2c4 --- /dev/null +++ b/docs/manual/custom-error.html @@ -0,0 +1,109 @@ +<HTML> +<HEAD> +<TITLE>Ccustom error responses</TITLE> +</HEAD> + +<BODY> +<IMG SRC="../images/apache_sub.gif" ALT=""> +<H1>Custom error responses</H1> +<DL> +<DT>Purpose +<DD>Additional functionality. Allows webmasters to configure the response of +Apache to some error or problem.<BR> +<P>Customizable responses can be defined to be activated in the event of a +server detected error or problem.<BR> +e.g. if a script crashes and produces a "500 Server Error" response, then +this response can be replaced with either some friendlier text or by a +redirection to another URL (local or external). +<DT>Old behavior +<DD>NCSA httpd 1.3 would return some boring old error/problem message which +would often be meaningless to the user, and would provide no means of logging +the symptoms which caused it.<BR><BR> +<DT>New behavior +<DD>The server can be asked to; +<OL> +<LI>Display some other text, instead of the NCSA hard coded messages, or +<LI>redirect to a local URL, or +<LI>redirect to an external URL. +</OL> +<P>Redirecting to another URL can be useful, but only if some information +can be passed which can then be used to explain and/or log the error/problem +more clearly.<BR>To achieve this, Apache will define new CGI-like environment +variables, e.g. +<blockquote><code> +REDIRECT_HTTP_ACCEPT=*/*, image/gif, image/x-xbitmap, image/jpeg <br> +REDIRECT_HTTP_USER_AGENT=Mozilla/1.1b2 (X11; I; HP-UX A.09.05 9000/712) <br> +REDIRECT_PATH=.:/bin:/usr/local/bin:/etc <br> +REDIRECT_QUERY_STRING= <br> +REDIRECT_REMOTE_ADDR=121.345.78.123 <br> +REDIRECT_REMOTE_HOST=ooh.ahhh.com <br> +REDIRECT_SERVER_NAME=crash.bang.edu <br> +REDIRECT_SERVER_PORT=80 <br> +REDIRECT_SERVER_SOFTWARE=Apache/0.8.15 <br> +REDIRECT_URL=/cgi-bin/buggy.pl <br> +</code></blockquote> + +note the <code>REDIRECT_</code> prefix. <p> + +At least <code>REDIRECT_URL</code> and <code>REDIRECT_QUERY_STRING</code> will +be passed to the new URL (assuming it's a cgi-script or a cgi-include). The +other variables will exist only if they existed prior to the error/problem.<p> + +<DT>Configuration +<DD><em>file: </em>server configuration<BR> +<P>Here are some examples... +<blockquote><code> +ErrorDocument 500 /cgi-bin/crash-recover <br> +ErrorDocument 500 "Sorry, our script crashed because %s. Oh dear<br> +ErrorDocument 500 http://xxx/ <br> +ErrorDocument 404 /Lame_excuses/not_found.html <br> +ErrorDocument 401 /Subscription/how_to_subscribe.html +</code></blockquote> +The syntax is, <p> +<code><A HREF="core.html#errordocument">ErrorDocument</A></code> +<3-digit-code> action <p> + +where the action can be, +<OL> +<LI>Text to be displayed.<BR>Prefix the text with a quote ("). Whatever +follows the quote is displayed. If the error/problem produced any additional +information, it can be specified using <code>%s</code>. +<em>Note: the (") prefix isn't displayed.</em> +<LI>An external URL to redirect to. +<LI>A local URL to redirect to. +</OL> +<P><code>ErrorDocument</code> definitions are sensitive to a +<code>SIGHUP</code>, so you can change any of the definitions or add new ones +prior to sending a <code>SIGHUP</code> (kill -1) signal. +</DL> +<P><HR><P> + +<h2>Custom error responses and redirects</H2> +<DL> +<DT>Purpose +<DD>Apache's behaviour to redirected URLs has been modified so that additional +environment variables are available to a script/server-include.<p> + +<DT>Old behaviour +<DD>Standard CGI vars were made available to a script which has been +redirected to. No indication of where the redirection came from was provided. +<p> +<DT>New behaviour +<DD>A new batch of environment variables will be initialized for use by a +script which has been redirected to.<BR> +Each new variable will have the prefix <code>REDIRECT_</code>.<BR> +REDIRECT_ environment variables are created from the CGI environment +variables which existed prior to the redirect, they are renamed with a +REDIRECT_ prefix, i.e. HTTP_USER_AGENT -> REDIRECT_HTTP_USER_AGENT.<BR> +In addition to these new variables, Apache will define +<code>REDIRECT_URL</code> and <code>REDIRECT_STATUS</code> to help the script +trace its origin.<BR> +Logging: both the original URL and the URL being redirected to, will +now be logged correctly in the access log.<p> +</DL> +<P><HR> + +<A HREF="../"><IMG SRC="../images/apache_home.gif" ALT="Home"></A> +<A HREF="./"><IMG SRC="../images/apache_index.gif" ALT="Index"></A> +</BODY> +</HTML> |