mod rewrite rule to replace + with -

I have a rewrite rule which replaces underscores with hyphens:

RewriteRule ^([^_]*)_([^_]*_.*) $1-$2 [N]

RewriteRule ^([^_]*)_([^_]*)$ /$1-$2 [L,R=301]

This rule is great because it will check recursively so it turns /word1_word2/ into /word1-word2/

But also works for /word1_word2_word3_word4/ into /word1-wor开发者_如何学Pythond2-word3-word4/

How can I modify this to replace the + symbol with a - (hyphen)?

So that /word1+word2/ turns into /word1-word2/

and

/word1+word2+word3+word4/ turns into /word1-word2-word3-word4/

I've tried a dozen variations and cant seem to get this to work.

Just add the character everywhere where you have an underscore:

RewriteRule ^([^_+]*)[_+]([^_+]*[_+].*) $1-$2 [N]

RewriteRule ^([^_+]*)[_+]([^_+]*)$ /$1-$2 [L,R=301]