Remove specific character that repeats more than once, and leave only one

Question

I've looked at answers of how to remove duplicate words for the last 20 minutes, trying to make them work for my use case, but that didn't work.

I have a small command that deletes special characters and transforms spaces into dashes,

echo "[[[h[el]lo - w{o}rld%^& -text" | tr -d '?$#@;:/\="<>%{}|^~[]&`' | tr ' ' '-'

and that produces the following output

hello---world--text

That runs perfectly, but I also want to add something else to that command, maybe another pipe, that removes the dashes that repeat

ex: I want it to transform, from the produced output, to:

hello-world-text

How can I do this in the most POSIX compliant way possible?

PS: Please tell me if there's a more efficient way to accomplish what I already made there

Answer 1

You can use the -s flag for that:

echo "[[[h[el]lo - w{o}rld%^& -text" | tr -d '?$#@;:/\="<>%{}|^~[]&`' | tr -s ' ' '-'

---

-s, --squeeze-repeats
              replace each sequence of a repeated character that is listed in the  last
              specified SET, with a single occurrence of that character