The environment must exist, and its name must be given as string literal in 'env_name'! The value of the variable 'v' will be stored under the name given in 'v_name'. If 'v_name' is not given, a variable name will be created by increasing an internal counter and using the its value padded with zeros as name (i.e., "0001", "0002" etc).
appendEnv(env_name, v, v_name = NULL)String of the environment variable
Value to be inserted
String used as variable name. Automatically generated if omitted.
Always TRUE