There are several extensions used for backup files: .0, .1, .old, .bak, .backup, .bkp, .baka, etc. Based on Reddit votes, the most used is .bak; therefore, we should use the extension used by common sense.
Specification:
- A backup file must be named with the extension .bak
- If there are multiple backups, the next backup extension must be added with an integer, e.g., .bak1, .bak2, etc.
- The above rules also apply for folder or directory, e.g., folderA.bak, dirB.bak1.
Finding all backup files
To find all backup files, simply use a shell command
$ ls *.bak* a.bak a.bak0 a.bak1 a.bak2