2.3.55 Header
Header customizes the response header when responding to the status code of the 200 series.
Description
Header customizes the response header when responding to the status code of the 200 series. When using this as a reverse proxy, the response header is customized regardless of the value of the status code returned from the backend web server.
Note that the mod_headers module needs to be implemented to customize the response header.
LoadModule headers_module modules/mod_headers.so
Syntax
Header{{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 Header directive when the specified environment variable is set.
- env=!environment_variable
-
Execute the content specified in the Header 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
Example
Header set Cache-Control no-cache