Talk:Bak file

this page is a description of backup files with extension .bak. It also describes its relation with some popular applications and the way to use them. Aravind V R (talk) 10:13, 26 January 2009 (UTC)

Append or replace extension? Hard-coded or optional behaviour?
When a program is about to overwrite an existing file (for example, when the user saves the document he or she is working on), the program may first make a copy of the existing file, with .bak appended to the filename.

My experience is that .bak normally replaces the original filename extension, rather than being appended to it. Though probably most of the programs I've seen producing .bak files were for MS-DOS or Windows 2 or 3. Of course, under 32-bit Windows or Unix-type systems, appending .bak is an available option, so I imagine that some programs will append .bak (thereby avoiding clashes between backups of file.txt and file.doc, for example) and others will replace the original extension with it. Can somebody with more experience of modern apps with this functionality comment on this?

Moreover, while it gives a partial list of apps that support .bak generation, until just now it didn't comment on whether it always does it or has a configuration setting to do it. I remember some old DOS programs being hard-coded to write a .bak file when you save a new version of a file. Is it ever hard-coded behaviour in modern apps, or is it always a configurable setting if available at all?

Other naming schemes are also in widespread use: file~, file.orig, file.old, and so on.

Are these used for auto-generated backups? In my time I would use .old for manual backups - I don't recall ever seeing a program automatically generate backup files with this extension. The only other extension I remember seeing for automatic backups of the sort being talked about here is .bkp, which was used by good old Windows Write. — Smjg (talk) 01:20, 4 April 2014 (UTC)