Add new line with sed

Question

Hello,
I try to insert a new lines after a model line with a sed command in a script ,like :
Before :
### model line#####
After :
### model line#####
new line 1
new line 2
I try something like this, but the newlinecharacter in not good understand :
sed -e"s/### model line#####/### model line#####\nnew line 1\nnew line 2/g" my.cnf
Some know how do that ??
Thx

Answer 1

to append newlines using sed, do not do it on cmd-line, because the shell will interprete the script,
so put in 'sedcmd' something like:
#-------begin
/muster/a\
linea
lineb
linec
#---------end, note the last blanc line, is NEEDED!
this also works for 'i' insert
to change/delete blanc lines, you need to know what is a blanc line
sed 's/^$/:/g'
will replace blanc lines by ':'
sed '/^$/d'
will delete blanc lines
finally sed has troubles w/ special characters, but it is NOT a bug!
kind regards, jms