- sysctl
int sysctl(int* name, uint namelen, void* oldp, size_t* oldlenp, void* newp, size_t newlen)
- sysctlbyname
int sysctlbyname(char* name, void* oldp, size_t* oldlenp, void* newp, size_t newlen)
- sysctlnametomib
int sysctlnametomib(char* sname, int* name, size_t* namelenp)
D header file for Darwin sys/sysctl.h