[R] removing zero rows from matrix/table

[Patrick Zimmermann]

Dear R-community,
I have matrices/tables of different sizes which may contain rows with
only zeros. Now I would like to delete these zero lines or create new
matrices composed only of the non-zero lines. Columns only containing
zeros I want to preserve.
Here an example:

[,1] [,2] [,3] [,4] [,5] [,6] [,7]
[1,] 1 0 1 1 0 0 0
[2,] 0 0 0 0 0 0 0
[3,] 1 0 0 0 0 0 0
[4,] 1 0 1 1 1 1 1
[5,] 1 0 1 0 1 0 1
[6,] 0 0 1 1 1 1 1
[7,] 0 0 0 0 0 0 0

Rows 2 and 7 shall be deleted, but column 2 shall be maintained.
I believe this should be a simple operation with basic commands, but
have no idea how to manage it.
Looking forward do any help,
Patrick