Using sed to add commas to new lines.

[lynxus]

Hi Guys,
I have some data like below:

interface Vlan1
description Management LAN
interface Vlan41
description Somelan
interface Vlan65
description Some other lan.
service-policy input 2Mbps
service-policy output 2Mbps

How can i get sed to look at this txt file and add a comma at the beginning of every new line between the interface lines.

IE:
interface Vlan1
,description Management LAN
interface Vlan41
,description Somelan
interface Vlan65
,description Some other lan.
,service-policy input 2Mbps
,service-policy output 2Mbps


Any ideas?

Thanks
Graham

[distributer]

I would try to define lines that do not match the "interface" thing.

something like (not sure I am on windows here -.-):

sed 's/^[^interface]/,/' test.txt

the ^ before the brackets means at the beginning of each line and inside the brackets means does not... hope this helps.

//edit: lol just noticed you were looking for the word "interface"

[ghostdog74]

the sed command is wrong. please check your output

$ awk '!/interface/{$0=","$0}1' file