请问 :Contact or wait for the long term?

Need Help! Contact or wait for the long term?

I am laid off two months ago. Just now got a contact offer (6 month), I was asked to sign it by tomorrow. I also interviewed with a long-term position, like the job very much, but not sure if I can get it and don’t know when they will make the decision.

If I sign up the contact but leave only after a few weeks of service, would the contract company do anything bad on me? Thanks very much.