Feature request: --sort option

["Brian L. Matthews" <blmatthews@gmail.com>]

On macOS at least, tarsnap processes a directory in an effectively 
random order (I suppose it's probably creation order). Unfortunately 
that makes watching -v or using SIGINFO not very useful, as knowing what 
file is being processed doesn't tell me much when I don't know if it's 
the first or last or somewhere in between. GNU tar has a --sort option 
that can be used to lexicographically sort each directory's contents. 
While that would take more memory, on modern systems it doesn't seem 
like it would be a problem, and it could be forced off under --lowmem 
(or cause an immediate error if they're both specified). Looking at the 
source, it seems like it would just take a couple of changes to 
tree_next in tar/tree.c (although admittedly I spent about 10 seconds 
looking at it :-) ).

Thanks,
Brian