what's modafinil?

It’s said that modafinil is a medicine made in America and only 1 tablet makes you able to work continuously in 40 hours without any sleep or rest. After that, you can have a sleep of 8 hours and then work another 40 hours. Is it on sale? (I cannot find it on market) Does it harm to body? I’m a sleepy dog, and even 9 hours for sleep if not enough for me. Is there any way to make me sleep less? Coffee has no use for me, which just makes me extra excited.

See …

http://www.nlm.nih.gov/medlineplus/druginfo/uspdi/203466.html
Hint: Google is your friend.