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，翻譯過來的意思應該是如果設置了matchBase，則會匹配底層路徑，即abc之后不帶斜杠，而不會匹配帶了斜杠的。

如果不對，煩請指正。