Will bankruptcy stop an eviction, or unlawful detainer, action?

Sometimes it will, but it is usually not a good idea. The owner is entitled to possession of his property and at best the debtor will only gain a short delay. Filing a Chapter 7 solely to avoid an eviction might be considered an abuse of Chapter 7. If the Bankruptcy Court finds that this is true, then the court can immediately dismiss the bankruptcy and impose other legal and monetary sanctions on you.