Click above to get retro games delivered to your door ever month!

The set of environment names and the method for altering the environment
list used by the  getenv function (7.10.4.4).

The set of environment names is unlimited.  Environment variables can be set
from the DOS command line using the SET command.  A program can modify its
environment variables with the  putenv function.  Such modifications last
only until the program terminates.