what is the use of -c parameter of column(1), can you demonstrate with an example?

[Zhang Weiwu <zhangweiwu@realss.com>]

 from man column(1)

     -c      Output is formatted for a display columns wide.

Try:

almustafa@orphalese:~$ echo aaa bbb | column  -c 20


expected result (17 spaces):

aaa                bbb

actual result:

almustafa@orphalese:~$ echo aaa bbb | column  -c 20
aaa bbb

Confusing. Or do I misunderstand the purpose of column(1)?

Thanks.