I want to add specific string at the end on each line that has some Strings and the blank line should stay unaffected.
How can I use the sed command so that the string i require is appened after only selected lines.

Say file name be temp.txt

```
abc "123.cf"
abc
abc "456.cf"
ksh
entry "e123.cf"

```

Now i want to append `> /dev/null 2>&1 &` to the end of each line that has .cf" in the end
and need the result to be 

```
abc "123.cf" > /dev/null 2>&1 &
abc
abc "456.cf" > /dev/null 2>&1 &
ksh
entry "e123.cf" > /dev/null 2>&1 &

```

I'm using the command: 

`sed -e 's:.cf"$:.ccf" > /dev/null 2>&1 &:' -i temp.txt`

Does'nt seem to work. :-(
Please help.