ref: 2bab10b60b3f4d3bbefdcb60410655f317d1a452 dir: /testdir/t.aeiouy/
/^[^aeiouy]*a[^aeiouy]*e[^aeiouy]*i[^aeiouy]*o[^aeiouy]*u[^aeiouy]*y[^aeiouy]*$/