From 2feece561853d63f2196d47d5c63c08c08bf70a5 Mon Sep 17 00:00:00 2001 From: Joshua Slive Date: Tue, 19 Jun 2001 03:48:49 +0000 Subject: [PATCH] Bring these docs into line with "The Standard" and clean them up a little. PR: Obtained from: Submitted by: Reviewed by: git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@89387 13f79535-47bb-0310-9956-ffa450edef68 --- docs/manual/mod/mod_headers.html | 233 +++++++++++++++---------------- 1 file changed, 110 insertions(+), 123 deletions(-) diff --git a/docs/manual/mod/mod_headers.html b/docs/manual/mod/mod_headers.html index 72b2ea0e55..a9983f63a3 100644 --- a/docs/manual/mod/mod_headers.html +++ b/docs/manual/mod/mod_headers.html @@ -15,7 +15,7 @@

Module mod_headers

-

This module provides for the customization of HTTP +

This module provides for the customization of HTTP request and response headers.

Header +

Order of Processing

+ +

The directives provided by mod_header can occur almost anywhere within +the server configuration. They are valid in the main server config and virtual +host sections, inside <Directory>, <Location> and <Files> +sections, and within .htaccess files.

+ +

The directives are processed in the following order: +

    +
  1. main server +
  2. virtual host +
  3. <Directory> sections and .htaccess +
  4. <Location> +
  5. <Files> +
+ +

Order is important. These two headers have a different effect if +reversed:

+ +
+RequestHeader append MirrorID "mirror 12"
+RequestHeader unset MirrorID +
+ +

This way round, the MirrorID header is not set. If reversed, the +MirrorID header is set to "mirror 12".

+ +

Examples

+
    +
  1. Copy all request headers that begin with "TS" to the response headers:
    2. +
    +   Header echo ^TS*
+
    + +
  2. Add a header, MyHeader, to the response including a timestamp for when +the request was received and how long it took to begin serving the +request. This header can be used by the client to intuit load on +the server or in isolating bottlenecks between the client and the +server.
    3. +
    +   Header add MyHeader "%D %t"
+
    +results in this header being added to the response: +
    +   MyHeader: D=3775428 t=991424704447256
+
    +
  3. Say hello to Joe
    4. +
    +   Header add MyHeader "Hello Joe. It took %D microseconds for Apache to serve this request."
+
    +results in this header being added to the response: +
    +   MyHeader: Hello Joe. It took D=3775428 microseconds for Apache to serve this request.
+
    + +
  4. Conditionally send MyHeader on the response if and only if header +"MyRequestHeader" is present on the request. This is useful for +constructing headers in response to some client stimulus. Note that +this example requires the services of the mod_setenvif module.
    5. +
    +   SetEnvIf MyRequestHeader value HAVE_MyRequestHeader
    
+   Header add MyHeader "%D %t mytext" env=HAVE_MyRequestHeader
+
    +If the header "MyRequestHeader: value" is present on the HTTP request, the response +will contain the following header: +
    +   MyHeader: D=3775428 t=991424704447256 mytext
+
    +
+

RequestHeader directive

@@ -82,10 +152,11 @@ replaced or removed. REL="Help" >Module: mod_header

-This directive can replace, merge or remove HTTP request headers. The header -is modified just before the content handler is run, allowing incoming -headers to be modified. The action it performs is determined by the first -argument. This can be one of the following values: +

This directive can replace, merge or remove HTTP request +headers. The header is modified just before the content handler is +run, allowing incoming headers to be modified. The action it performs +is determined by the first argument. This can be one of the following +values:

-This argument is followed by a header name, which can include the +

This argument is followed by a header name, which can include the final colon, but it is not required. Case is ignored. For -add, append and set a value is given as the third argument. If this -value contains spaces, it should be surrounded by double quotes. -For unset, no value should be given. - -

Order of Processing

- -The RequestHeader (and Header) directives can occur almost anywhere within -the server configuration. It is valid in the main server config and virtual -host sections, inside <Directory>, <Location> and <Files> -sections, and within .htaccess files. -

-The RequestHeader directives are processed in the following order: -

    -
  1. main server -
  2. virtual host -
  3. <Directory> sections and .htaccess -
  4. <Location> -
  5. <Files> -
+add, append and set a value is +given as the third argument. If this value contains spaces, it should +be surrounded by double quotes. For unset, no value should be +given.

-Order is important. These two headers have a different effect if reversed: -
-RequestHeader append MirrorID "mirror 12"
-RequestHeader unset MirrorID
-
- -This way round, the MirrorID header is not set. If reversed, the MirrorID -header is set to "mirror 12". -

- -The RequestHeader 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 input filters to be overridden or modified. -

+

The RequestHeader 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 input filters to +be overridden or modified.

@@ -179,10 +225,11 @@ the browser, or by Apache input filters to be overridden or modified. REL="Help" >Module: mod_header

-This directive can replace, merge or remove HTTP response headers. The header -is modified just after the content handler and output filters are run, -allowing outgoing headers to be modified. The action it performs is determined -by the first argument. This can be one of the following values: +

This directive can replace, merge or remove HTTP response +headers. The header is modified just after the content handler and +output filters are run, allowing outgoing headers to be modified. The +action it performs is determined by the first argument. This can be +one of the following values:

-This argument is followed by a header name, which can include the +

This argument is followed by a header name, which can include the final colon, but it is not required. Case is ignored for set, append, add and unset. The header name for echo is case sensitive and may be a -regular expression. -

-add, append and set take a value as the third argument. If -value contains spaces, it should be surrounded by doublequotes. +regular expression.

+ +

For add, append and set a +value is specified as the third argument. If value +contains spaces, it should be surrounded by doublequotes. value may be a character string, a string containing format specifiers or a combination of both. The following format specifiers are supported in value: @@ -228,83 +276,22 @@ are supported in value: headers are sent on the wire. This is a measure of the duration of the request. The value is preceeded by "D=". -add, append and set may take an optional conditional clause -as the fourth argument. The header action (add, append, set) is -done only if the conditional clause evaluates as TRUE. -

Order of Processing

+

When the Header directive is used with the +add, append, or set argument, a +fourth argument may be used to specify conditions under which the +action will be taken. If the environment +variable specified in the env=... argument exists (or +if the environment variable does not exist and env=!... +is specified) then the action specified by the Header +directive will take effect. Otherwise, the directive will have no +effect on the request.

+ +

The Header directives are processed just before the response is +sent to the network. These means that it is possible to set and/or +override most headers, except for those headers added by the header +filter.

-The Header (like the RequestHeader) directives can occur almost anywhere within -the server configuration. It is valid in the main server config and virtual -host sections, inside <Directory>, <Location> and <Files> -sections, and within .htaccess files. -

-The Header directives are processed in the following order: -

    -
  1. main server -
  2. virtual host -
  3. <Directory> sections and .htaccess -
  4. <Location> -
  5. <Files> -
- -Order is important. These two headers have a different effect if reversed: -
-Header append Author "John P. Doe"
-Header unset Author
-
- -This way round, the Author header is not set. If reversed, the Author -header is set to "John P. Doe". -

- -The Header directives are processed just before the response is sent -to the network. These means that it is possible to set and/or override -most headers, except for those headers added by the header filter. -

-

-

Examples

-
    -
  1. Copy all request headers that begin with "TS" to the response headers:
    2. -
    -   Header echo ^TS*
-
    - -
  2. Add a header, MyHeader, to the response including a timestamp for when -the request was received and how long it took to begin serving the -request. This header can be used by the client to intuit load on -the server or in isolating bottlenecks between the client and the -server.
    3. -
    -   Header add MyHeader "%D %t"
-
    -results in this header being added to the response: -
    -   MyHeader: D=3775428 t=991424704447256
-
    -
  3. Say hello to Joe
    4. -
    -   Header add MyHeader "Hello Joe. It took %D microseconds for Apache to serve this request."
-
    -results in this header being added to the response: -
    -   MyHeader: Hello Joe. It took D=3775428 microseconds for Apache to serve this request.
-
    - -
  4. Conditionally send MyHeader on the response if and only if header -"MyRequestHeader" is present on the request. This is useful for -constructing headers in response to some client stimulus. Note that -this example requires the services of the mod_setenvif module.
    5. -
    -   SetEnvIf MyRequestHeader value HAVE_MyRequestHeader
    
-   Header add MyHeader "%D %t mytext" env=HAVE_MyRequestHeader
-
    -If the header "MyRequestHeader: value" is present on the HTTP request, the response -will contain the following header: -
    -   MyHeader: D=3775428 t=991424704447256 mytext
-
    -
-- 2.40.0