Q. Is There a UNIX / Linux unerase or undelete command? How do I undelete files under a UNIX / Linux system?
A.. Short answer - no.
There is no "unerase" or "undelete" command in Linux / *BSD / Unix like operating system such as AIX or HP-UX . The best solution is to restore file from a backup. You can also use a data recovery tool but there is no guaranty you will get back the data. Always use following method to avoid problems:
=> Make regular backups and file system snapshots
=> Never ever login as root for non admin related tasks
=> Always use a regular user account for all normal tasks
=> Alias rm / mv / cp command as rm -i / mv -i
alias cp='cp -i'
alias mv='mv -i'
alias rm='rm -i'
=> Make important file copy before editing
=> Use RAID 6 or above hardware card as additional protection for file server
=> Keep files safe from accidental overwriting with noclobber under BASH shell
=> Make a Linux File unchangeable ( unalterable ) so that no one can modify it - including root user