From ff9fb31b019437e629423464b1964636d9ea543e Mon Sep 17 00:00:00 2001
From: Rich Bowen <rbowen@apache.org>
Date: Sat, 11 Aug 2007 12:15:08 +0000
Subject: [PATCH] Add a description of the env= optional syntax, as per issue
 #27951

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.0.x@564905 13f79535-47bb-0310-9956-ffa450edef68
---
 docs/manual/mod/mod_headers.html.en | 12 +++++++++++-
 docs/manual/mod/mod_headers.xml     | 13 ++++++++++++-
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/docs/manual/mod/mod_headers.html.en b/docs/manual/mod/mod_headers.html.en
index 044f111ad66..c9eb0859bfe 100644
--- a/docs/manual/mod/mod_headers.html.en
+++ b/docs/manual/mod/mod_headers.html.en
@@ -256,7 +256,7 @@ later</td></tr>
 <table class="directive">
 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configure HTTP request headers</td></tr>
 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>RequestHeader set|append|add|unset <var>header</var>
-[<var>value</var>]</code></td></tr>
+[<var>value</var> [env=[!]<var>variable</var>]]</code></td></tr>
 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr>
 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
@@ -299,6 +299,16 @@ later</td></tr>
     <var>value</var> contains spaces, it should be surrounded by double
     quotes. For unset, no <var>value</var> should be given.</p>
 
+    <p>When the <code class="directive">RequestHeader</code> directive is used with the
+    <code>add</code>, <code>append</code>, or <code>set</code>
+    argument, a fourth argument may be used to specify conditions
+    under which the action will be taken. If the <a href="../env.html">environment variable</a> specified in the
+    <code>env=...</code> argument exists (or if the environment
+    variable does not exist and <code>env=!...</code> is specified)
+    then the action specified by the <code class="directive">RequestHeader</code> directive
+    will take effect. Otherwise, the directive will have no effect
+    on the request.</p>
+
     <p>The <code class="directive">RequestHeader</code> directive is processed
     just before the request is run by its handler in the fixup phase.
     This should allow headers generated by the browser, or by Apache
diff --git a/docs/manual/mod/mod_headers.xml b/docs/manual/mod/mod_headers.xml
index af5f24fddb7..37363b5bdaf 100644
--- a/docs/manual/mod/mod_headers.xml
+++ b/docs/manual/mod/mod_headers.xml
@@ -142,7 +142,7 @@ is available only in Apache 2.0</compatibility>
 <name>RequestHeader</name>
 <description>Configure HTTP request headers</description>
 <syntax>RequestHeader set|append|add|unset <var>header</var>
-[<var>value</var>]</syntax>
+[<var>value</var> [env=[!]<var>variable</var>]]</syntax>
 <contextlist><context>server config</context><context>virtual host</context>
 <context>directory</context><context>.htaccess</context></contextlist>
 <override>FileInfo</override>
@@ -185,6 +185,17 @@ is available only in Apache 2.0</compatibility>
     <var>value</var> contains spaces, it should be surrounded by double
     quotes. For unset, no <var>value</var> should be given.</p>
 
+    <p>When the <directive>RequestHeader</directive> directive is used with the
+    <code>add</code>, <code>append</code>, or <code>set</code>
+    argument, a fourth argument may be used to specify conditions
+    under which the action will be taken. If the <a
+    href="../env.html">environment variable</a> specified in the
+    <code>env=...</code> argument exists (or if the environment
+    variable does not exist and <code>env=!...</code> is specified)
+    then the action specified by the <directive>RequestHeader</directive> directive
+    will take effect. Otherwise, the directive will have no effect
+    on the request.</p>
+
     <p>The <directive>RequestHeader</directive> directive is processed
     just before the request is run by its handler in the fixup phase.
     This should allow headers generated by the browser, or by Apache
-- 
2.47.2