Rows to wave

I am have a number of files with 1 single data set, but the output has 10
> columns with about 100 rows, i.e.
>
> a b c
> d e f
> g h i
>
> I need to transpose it to 1 single wave like this:
>
> a
> b
> c
> d
> e
> f
> g
> h
> i
>

Can anyone help me?

PiStosHiO17