Dave Cantrell wrote:
> I just tried the following in IRB:
>
> irb(main):005:0> r = `xcopy /s a\*.* b\*.*`
> Cannot perform a cyclic copy
> => "0 File(s) copied\n"

You need to escape your backslashes:
irb> "xcopy /s a\*.* b\*.*"
=> "xcopy /s a*.* b*.*"
irb> "xcopy /s a\\*.* b\\*.*"
=> "xcopy /s a\*.* b\*.*"

You might also consider Ruby's FileUtils.cp(). (I haven't used it, but it's 
there.)

Cheers,
Dave