[ale] Sed help with append

[Jim Seymour]

Hi,

I am trying to expand my capabilities with sed use. What I am trying
to do is modify an apache virt file as follows. The file containing
the lines to modify is named test.

<VirtualHost 12.34.567.89>
ServerAdmin webmaster at domain.com
ServerName domain.com
DocumentRoot /does/not/matter
</VirtualHost>

It needs a ServerAlias appended after ServerName as www.domain.com

What am I missing to get the pattern match in the append?

jim at swift ~ $ sed '/ServerName \(.*\)/ a\ServerAlias www.\1' test
<VirtualHost 12.34.567.89>
ServerAdmin webmaster at domain.com
ServerName domain.com
ServerAlias www.1
DocumentRoot /does/not/matter
</VirtualHost>

Have not been able to locate anything by googling about combining an
append with a remembered pattern. I even tried combining it into an
append the line and then do a substitute on the appended line to no
avail. I have a feeling there is probably something simple I have
missed somewhere.

Thanks,
-- 
Jim Seymour