sets the value of an operating system environment variable.
sets values for several environment variables.
- An environment variable defined in the current session is accessible within this session or in the child processes spawned by the Wolfram System, for example, when using Run or CreateLibrary.
- Values of environment variables, or merely their existence in the environment, may affect the behavior of certain Wolfram Language functions or child processes.
- The value or the existence of a defined variable is not preserved when the Wolfram System is terminated or restarted.
- If the variable "var" did not exist in the environment, its name is added to the environment with the associated "value".
- If the variable "var" already existed in the environment, its value is replaced with "value".
- Setting "var"->None removes the variable and its definition from the environment. If "var" did not previously exist, it will not be created.
- Setting "var"->"" does not remove the variable from the environment, but merely sets its value. If "var" did not previously exist, it will be created.
Introduced in 2012