#include <sicstus/sicstus.h> void * SP_getenv(const char *name);
Retrieves the value of the system property, or if no such system property exists the environment variable, with the given name.
The memory for the returned value is managed by Prolog and should be
The name of the system property or environment variable.
The value of the system property or environment variable, if
NULL if neither a system property nor an environment
variable of that name exists, or if an error occurs.
System Properties and Environment Variables.