it() rsync chooses between doing a simple string match and wildcard
matching by checking if the pattern contains one of these three wildcard
characters: '*', '?', and '[' .
- it() a '*' matches any non-empty path component (it stops at slashes).
+ it() a '*' matches any path component, but it stops at slashes.
it() use '**' to match anything, including slashes.
it() a '?' matches any character except a slash (/).
it() a '[' introduces a character class, such as [a-z] or [[:alpha:]].