Htaccess recursively replace underscores with hyphens

Question

I\'m trying to redirect all URLs with underscores to the same URL but with underscores replaced by hyphens.

I\'ve tried many examples online but these either provide

Answer 1

You can use that:

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

After @anubhava explanation. If big number of underscores can be a problem. You can use that (without variables):

RewriteRule ^([^_]*)_([^_]*)_([^_]*)_([^_]*_.*)$ $1-$2-$3-$4 [L,NE]
RewriteRule ^([^_]*)_([^_]*_.*)$ $1-$2 [L,NE]
RewriteRule ^([^_]*)_([^_]*)$ /$1-$2 [L,NE,R=301]