Re: Order of files with 'cp'

# Brian Candler:
> > This just adds a -o flag to cp, which preserves order.
> 
> Hmm, that's another solution that I hadn't thought of.
> 
> Advantages: simple to implement. (Even simpler if you use the ?: operator).

*Shrug* I tend to avoid that operator, as it doesn't exactly
help code's readability imo, but that's just taste.


> Disadvantages: it's still strange that the default behaviour is to copy the
> files in an arbitary shuffled order. 

Interestingly enough, mastercmp()s comment is actually off:

 *  The comparison function for the copy order.  The order is to copy
 *  non-directory files before directory files.  The reason for this
 *  is because files tend to be in the same cylinder group as their
 *  parent directory, whereas directories tend not to be.  Copying the
 *  files first reduces seeking.

$ mkdir a b c && touch 1 2 3
$ cp -rv a 1 3 2 b c
b -> c/b
a -> c/a
2 -> c/2
3 -> c/3
1 -> c/1

Which is directories _first_, then other files, both sorted
in reverse order (with regard to the way they're specified
on the command line).

Sorting isn't entirely stable however:

$ cp -rv 6 5 4 3 2 1 a c
a -> c/a
1 -> c/1
2 -> c/2
4 -> c/4
5 -> c/5
6 -> c/6
3 -> c/3  # <-- what's that doing here?


> Commands arguably have too many flags already.

Agreed.  Just how much does cp gain using mastercmp(), anyway?
I doubt it's much faster with it and it'd certainly be easiest
to remove it and always use fts_open(.,.,NULL) instead.

Regards,
Mario