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 did not exist in the environment, its name is added to the environment with the associated .
- If the variable already existed in the environment, its value is replaced with .
- Setting "var"->None removes the variable and its definition from the environment. If did not previously exist, it will not be created.
- Setting does not remove the variable from the environment, but merely sets its value. If did not previously exist, it will be created.
Introduced in 2012