linux - How to replace to apostrophe ' inside a file using SED

Question

I have a file "test.txt" that contain the following

+foo+
+bar+

What I want to do is to replace them into:

'foo'
'bar'

But why this code doesn't work?

sed  's/+/'/' test.txt

What's the right way to do it?

Answer 1

Use " instead. And add g flag to replace all.

sed  "s/+/'/g" test.txt