#BUILD
make
sudo make install
#RUN
htod : convert HEX to DEC
Ex, htod fee1c001
dtoh : convert DEC to HEX
Ex, dtoh 4276207617
gettimeofday : get current time(UNIX timestamp)
Ex, gettimeofday
ctime : convert UNIX timestamp to string
Ex, ctime 1461570588 1461570598