ref: 416c6db5ee829b5e97dc8001b28e475fd942dbb6 dir: /testdir/t.aeiouy/
/^[^aeiouy]*a[^aeiouy]*e[^aeiouy]*i[^aeiouy]*o[^aeiouy]*u[^aeiouy]*y[^aeiouy]*$/