This should be easy: I want to run sed against a literal string, not an input file. If you wonder why, it is to, for example edit values stored in variables, not necessarily text data.
When I do:
sed 's/,/','/g' "A,B,C"
where A,B,C is the literal which I want to change to A','B','C
I get
Can't open A,B,C
As though it thinks A,B,C is a file.
I tried piping it to echo:
echo "A,B,C" | sed 's/,/','/g'
I get a prompt.
What is the right way to do it?