If you intend to file a bankruptcy then filing it before the unlawful detainer action (eviction) will delay the eviction.
However, if the house was taken back by the bank or mortgage company at the foreclosure sale and you contact the agent that delivered the "5-day notice", you may be able to negotiate more time and even some money to move. Many of the REO ("Real Estate Owned" by a bank or mortgage lender) management companys are offering a program called "cash-for-keys". The going rate in this area is between $3000 and $1500 which will be given to the tenant or former owner at the time they vacate. The incentive for offering this financial "carrot" is the agreement that you will leave the house in good condition and move out without delay on the agreed date. Hope this helps.
This answer in no way creates an attorney-client relationship. The answer is not a complete answer and requires additional facts in order to provide the best options. The submitter accepts the risk of relying on such an incomplete answer and waives any claims of damages for doing so. As stated in the answer the submitter should contact a qualified bankruptcy attorney is discuss these issues further before any action is taken. Any action taken without advise and counsel of a qualified attorney is inadvisable.
If the foreclosure was valid, there is no long-term solution. You will have to vacate. But a bankruptcy case will stay the eviction temporarily. Whether that is a wise move depends on the facts and circumstances of your case.