Retrieves the value of the environment variable with the given name, or a default value if the variable doesn't exist.
Identify whether a variable is defined in the environment.
Retrieves the value of the environment variable with the given name.
Assigns the given value to the environment variable with the given name. If value is null the variable is removed from environment.
Removes the environment variable with the given name.
Copies all environment variables into an associative array.
Manipulates environment variables using an associative-array-like interface.
This class contains only static methods, and cannot be instantiated. See below for examples of use.