matchBase If set, patterns without slashes will be matched against the basename of the path if it contains slashes. For example, a?b would match the path /xyz/123/acb, but not /xyz/acb/123.

引自gruntAPI，翻译过来的意思应该是如果设置了matchBase，则会匹配底层路径，即abc之后不带斜杠，而不会匹配带了斜杠的。

如果不对，烦请指正。