How do i replace [] brackets using SED

Question

I have a string that i am want to remove punctuation from.

I started with

sed \'s/[[:punct:]]/ /g\'

But i had problems on HP-UX n

Answer 1

Here is the final code I ended up with

`echo "$string" | sed 's/[^a-zA-Z0-9]/ /g'`

I had to put = and - at the very end.