Change composer global path (Windows)

Question

Composer uses %APPDATA%\\Composer directory by default for global packages.
So I need to add %APPDATA%\\Composer\\vendor\\bin path to my user P

Answer 1

I found an answer in the source code: https://github.com/composer/composer/blob/master/src/Composer/Factory.php#L45

So environment variable COMPOSER_HOME must be defined as C:\php\composer.