How to use system environment variables in php.ini with IIS - php

Question

I've found that when executing php via cli php has access to custom windows system environment variables, but not when IIS runs php.
For example, I can put this in php.ini:
zend_extension="${PHP_PATH}ext\php_xdebug-2.5.5-7.1-vc14-nts.dll"
and php loads xdebug properly when called via cli:
c:\>php.exe -v
MSVC14 (Visual C++ 2015) x86 ) Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.1.0, Copyright (c) 1998-2017 Zend Technologies
with Zend OPcache v7.1.1, Copyright (c) 1999-2017, by Zend Technologies
with Xdebug v2.5.5, Copyright (c) 2002-2017, by Derick RethansPHP 7.1.1 (cli) (built: Jan 18 2017 18:50:48) ( NTS
But Xdebug doesn't appear when I call phpinfo() on a page served by IIS. I'm assuming it's because IIS doesn't have access to the custom system variable I created. Can someone show me how to make those variables accessible in IIS, preferably in a way that I can script (whether that be via batch file, power shell or whatever) for automated deployments.

Answer 1

So I found that when executing setx from the command line or a batch file like:
setx PHP_PATH {path to php here}
it creates the system variable in the user space. Since IIS doesn't have access to it, php.ini variables can't be expanded. However, if you pass the /M flag, like the following:
setx /M PHP_PATH {path to php here}
this creates a variable in the global space that IIS does have access to.