How to Undo overwrite file in UNIX?

Hi,

Could anyone please advise if its possible in unix to undo the changes for a file that has been overwrriten.
By mistake i have overwritten a file and now i need the original file, is there a way?

Please Help!!!

No. There is no "undo" command.

You should always make a backup copy of a file before you edit it; and you should always have backup copies of all files you don't want to "lose" if the files are important.

There will always be mistakes, typos, errors by humans working on computer systems. Systems will crash, drives will fail, power will go down; so you must work assuming mistakes will happen and systems may crash, and insure you have backups as you work, at all times.

Okay.