Read real-time power consumption from Mac hardware.
make && ./syspowerPSTR (System Total): 13.0979
PCPC (CPU package CPU): 1.125
PCPG (CPU package GPU): 0.046875
PCPT (CPU package Tot): 13.0979
PG0R (GPU 0 rail): 0.0740947
PSTR (System Total): 14.3846
PCPC (CPU package CPU): 0.882812
PCPG (CPU package GPU): 0.015625
PCPT (CPU package Tot): 14.3846
PG0R (GPU 0 rail): 0.0730083
…and so on, once per second.