UNIX command to ignore replacing a search string if it is already present

UNIX for Beginners Q & A
1

Hello,

I am searching the following string Folder^ in a file and replacing it with Folder^/
However if the file already contains Folder^/ I want to avoid replacing it with Folder^//

To do this I have to do the following today:
1) echo "Folder^" | sed 's/Folder\^/Folder\^\//g'
I get "Folder^/"
2) echo "Folder^/" | sed 's/Folder\^/Folder\^\//g'
I get "Folder^//"

Is there a way in awk or sed to do this a single command. I know I can do the following - but I am looking for a more smarter way to do this
1) replace Folder^/ by Folder^

sed 's/FOLDER\^\//FOLDER\^/g'

2) replace Folder^ by Folder^/

sed 's/FOLDER\^/FOLDER\^\//g'
2

Try

sed 's/Folder\^\/*/Folder\^\//g'

or e.g.

sed 's#Folder\^/*#Folder^/#g'
3

Or

sed 's|\(Folder^\)/*|\1/|g'