Writes an environment variable.
EnvSet ( "envvariable" [, "value"] )
| envvariable | Name of the environment variable to set. |
| value | [optional] Value to set the environment variable to. If a value is not used the environment variable will be deleted. |
| Success: | Returns not 0. |
| Failure: | Returns 0. |
EnvSet("MYENV", "this is a test")