3 ms·
I don't know about DEC-20, but on VMS, changing a file makes a copy with a new version number: $ edit foo.txt ... Ctrl-Z $ dir foo.txt;1 $ edit foo
by SloopJon 6y ago
I don't know about DEC-20, but on VMS, changing a file makes a copy with a new version number:
$ edit foo.txt
...
Ctrl-Z
$ dir
foo.txt;1
$ edit foo.txt
...
Ctrl-Z
$ dir
foo.txt;1 foo.txt;2
When you delete a file, you have to specify a version field (blank for latest):
$ del foo.txt;
$ dir
foo.txt;1
IIRC, you can configure how many versions to keep.
- vincent-manis 6y agoThe version number was used the same way in TOPS-20 (which I never used) and Tenex, its predecessor (which I did). Emacs still has a facility for numbering backup files in the same way.
- tragomaskhalos 6y agoYes that's right, the versions to retain was configurable, and the whole versioning mechanism was really useful and a great miss from today's OSes. The VMS file and directory syntax otoh was a real pain, Unix definitely wins there.