Generating generations of files

Grant Edwards grant.b.edwards at gmail.com
Tue Apr 30 11:10:50 EDT 2019


On 2019-04-30, Cameron Simpson <cs at cskk.id.au> wrote:
> On 30Apr2019 11:24, DL Neil <PythonList at DancesWithMice.info> wrote:
>>On 30/04/19 8:17 AM, MRAB wrote:
>>>Why would generation numbers result in a 'ripple' of renaming?
>>>
>>>You're assuming that "output.rpt.1" comes after "output.rpt.2", but 
>>>it could just as well come before (generation 1 precedes generation 
>>>2, etc.). You're just left with the exception of the unnumbered 
>>>"output.rpt" being the latest.
>>
>>I was!
>>
>>However, that's the way statisticians and mathematicians think, and 
>>thus expressed themselves (I 'swapped' the minus-sign for a fileNM 
>>separator):
>>
>>(current) version	version.rpt
>>-1 version		version.rpt.1
>>-2 version		version.rpt.2
>>etc
>
> For a counter example, I'm pretty sure the VMS built in file versioning 
> went on the scheme MRAB described: rewriting version.rpt caused the old 
> version to become "version.rpt;n" where n counted up from 1.

That sounds right.

And you could configure how many versions were kept.  I usually set it
to 3.  I'm not sure, but I vaguely remember it might have been limited
at 32767.

-- 
Grant Edwards               grant.b.edwards        Yow! I know how to do
                                  at               SPECIAL EFFECTS!!
                              gmail.com            



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