2.3.121 RequestHeader

Description

RequestHeader customizes the header value received from the client.

Note that the mod_headers module needs to be implemented to customize the response header.

LoadModule headers_module modules/mod_headers.so

Syntax

RequestHeader {{set|append|add}header header_value[env=[!]environment_variable]|unset header}

Specifiable values

set

Set the header. If the header already exists, it will be replaced with the specified header value.

append

Add the header value to the existing header. A comma is placed to separate the headers. A header is set when no header exists.

add

Set the header to a new line even if the header exists. Use this value to set the same header in multiple lines.

unset

When a specified header exists, delete the entire header.

env=environment_variable

Execute the content specified in the RequestHeader directive when the specified environment variable is set.

env=!environment_variable

Execute the content specified in the RequestHeader directive when the specified environment variable is not set.

header_value

A character string composed of characters only, a character string composed of a format directive, or a character string composed of both can be specified.

The header value must be enclosed in double quotation marks (") when the header value contains a space.

The format directives are as follows:

Format directive	Meaning
%t	Displays the time when the request was received, from the amount of time that has elapsed since midnight on January 1st, 1970 (GMT: Greenwich Mean Time). The units are in microseconds. t= is attached at the beginning.
%D	Displays the time taken for processing the request. The units are in microseconds. D= is attached at the beginning
%{env_name}e	Displays the value for the environment variable set in env_name.

Locations where it can be written

httpsd.conf, <VirtualHost>, <Directory> and .htaccess

Overwrite permission

FileInfo level

RequestHeader set Host www.example.com