In the header of the HTTP request, why do you sometimes have x-powered-by this value, sometimes not?

X-powered-by is not an Apache or nginx output, but is output by a language parser or application framework, meaning that this value is used to tell the website which language or framework is written.
For example:

• Php

PHP standard output is: x-powered-by:php/5.2.1, can be added in the php.ini or modified to expose_php = Off close.

• thinkphp

and using the thinkphp, will output: x-powered-by:thinkphp 2.0, can modify the related class file close

• . Net

With. NET output: X-powered-by:asp.net, can be modified to web.config delete

Nginx compile time can add a module, Httpheadersmore, used to uniformly delete or modify the returned HTTP header.

Key content In addition, the Web server itself will spit out its own version number, HTTP header is server:xxxxx, which sometimes caused someone to specifically exploit a specific version of the Web server vulnerability to attack, Nginx can be added to the configuration file or modified server_tokens off to remove the version number.

The above describes the HTTP request header inside, why sometimes there is x-powered-by this value, sometimes not? , including the aspects of the content, want to be interested in PHP tutorial friends helpful.

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