How to use sed command for change special lines?

Shell Programming and Scripting
1

Hi,

I want to add a character "#" in this few lines with sed command

Initial:

### CACCIA: DEBUT ###
if $(grep -wqi "$2" /etc/passwd); then
        chuser -R files registry=files $2
fi
### CACCIA: FIN ###

Result with sed command:

### CACCIA: DEBUT ###
#if $(grep -wqi "$2" /etc/passwd); then
#        chuser -R files registry=files $2
#fi
### CACCIA: FIN ###

Thank you

2

Something like this:

sed 's/^[^#].*/#&/' file
3

Or even:

sed 's/^[^#]/#&/' file

-or-

sed '/^#/!s/^/#/' file
4 
awk '!/^#/ {$0="#"$0}1 ' urfile
5

Hi,

thank you for your reply.
But, i forget to tell that this lines are in a file with other lines.

I have the character "#" in all file.

thank you