Funnily enough, some years ago I was experimenting with the SCM tool ‘arch’, which creates very long paths which made it unusable in Windows. One approach that was being investigated in the arch community was to exploit an interesting feature in Windows. Unicode paths can be longer than 256 chars, so if you prepend \?\ to the start of the path then it looks Unicode-ish, and some APIs will work.

The idea was to add a thunking layer to Cygwin which would intercept long paths, and use the Unicode paths instead.

I did some investigation myself, and did indeed get some of it to work. There were a few APIs that still didn’t support the Unicode hack, but there was usually a way around it.

In the end, MS released Services For Unix, which did work correctly with long paths.

I’ve only tried it between Mac and Unix machines. Extremely fast and accurate.

Bob responds: Thanks, but I’m a little wary of a site that starts out with the comment, “The rsync provided here is very old. There are many known bugs, and some of these may cause data corruption.” After all, I already have known bugs with Windows Explorer, but as far as I know, no data corruption. If you don’t mind rsync’s Cygwin baggage, one of the other links on that page to more recent updates / re-packagings of rsync might be worth looking into, though.