Simplest way to clobber/replace one populated directory with another?

[Cameron Simpson]

On 15May2018 09:37, Travis Griggs <travisgriggs at gmail.com> wrote:
>I have a directory structure that might look something like:
>
>    Data
>        Current
>            A
>            B
>            C
>        Previous
>            A
>            X
>
>In as simple/quick a step as possible, I want to rename Current as Previous including the contents and wiping out the original such that it is now:
>
>    Data
>        Previous
>            A
>            B
>            C
>
>I've tried something like:
>
>    from pathlib import Path
>    src = Path('Data/Current’)
>    dest = Path('Data/Previous’)
>    src.replace(dest)
>
>The docs led me to hope this would work:
>
>    "If target points to an existing file or directory, it will be unconditionally replaced.”
>
>But it *does* appear to be conditional. I get a "Directory not empty" 
>exception. I guess I could recursively delete the ‘Previous' directory first. 
>Is that basically the only solution? Or is there a better way to achieve this?

When I do this and want speed I go:

1) rename Previous to a scratch name (eg .rmtmp-$$-Previous; the mkstemp 
function will help pick a free name for you). Make sure it is in the same 
directory i.e. rename blah/blah/Previous to blah/blah/.rmtmp-$$-Previous) - 
avoids accidentally crossing filesystem boundaries.

2) rename Current to previous

3) remove the old previous (I do this asynchronously in shell scripts)

In fact I do this so often in the shell that I have a trite script called "rmr" 
that does 1+3, and routinely type:

  rmr Previous && mv Current Previous

Prompt back instantly, "rm" of the temp name proceeding siletnly in the 
background.

Cheers,
Cameron Simpson <cs at cskk.id.au>