Mod Rewrite : Replace all _ (underscore) with - (hyphen)

Question

I need to have all _ (underscores) in every url to be replaced with - (hyphens)

I currently do it this way, but am looking for a more simpler way of doing this so I do not have to add a line every time a url gets longer.

RewriteRule ^([^_]+)-([^_]+)-([^_]+)-([^_]+)-([^_]+)-([^_]+)-([^.]+)-([^.]+)-([^.]+)-([^.]+)$ index.php?/$1_$2_$3_$4_$5_$6_$7_$8_$10 [L]
RewriteRule ^([^_]+)-([^_]+)-([^_]+)-([^_]+)-([^_]+)-([^_]+)-([^.]+)-([^.]+)-([^.]+)$ index.php?/$1_$2_$3_$4_$5_$6_$7_$8_$9 [L]
RewriteRule ^([^_]+)-([^_]+)-([^_]+)-([^_]+)-([^_]+)-([^_]+)-([^.]+)-([^.]+)$ index.php?/$1_$2_$3_$4_$5_$6_$7_$8 [L]
RewriteRule ^([^_]+)-([^_]+)-([^_]+)-([^_]+)-([^_]+)-([^_]+)-([^.]+)$ index.php?/$1_$2_$3_$4_$5_$6_$7 [L]
RewriteRule ^([^_]+)-([^_]+)-([^_]+)-([^_]+)-([^_]+)-([^.]+)$ index.php?/$1_$2_$3_$4_$5_$6 [L]
RewriteRule ^([^_]+)-([^_]+)-([^_]+)-([^_]+)-([^.]+)$ index.php?/$1_$2_$3_$4_$5 [L]
RewriteRule ^([^_]+)-([^_]+)-([^_]+)-([^.]+)$ index.php?/$1_$2_$3_$4 [L]
RewriteRule ^([^_]+)-([^_]+)-([^.]+)$ index.php?/$1_$2_$3 [L]
RewriteRule ^([^_]+)-([^.]+)$ index.php?/$1_$2 [L]

Thanks.

Answer 1

mod_rewrite is not a good tool for that kind of work. Why don’t you replace with PHP?

$_SERVER['QUERY_STRING'] = str_replace('_', '-', $_SERVER['QUERY_STRING']);

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Edit    Well you could try these rule sets:

# using the path
RewriteRule ^([^-]+)-([^-]+-.+) /$1_$2 [N]
RewriteRule ^([^-]+)-(.+) index.php?/$1_$2 [L]

# using the query
RewriteRule ^([^-]+)-(.+) index.php?/$1_$2
RewriteCond %{QUERY_STRING} ^([^-]+)-(.+)
RewriteRule ^index\.php$ ?$1_$2 [N]
RewriteRule ^index\.php$ - [L]

But be careful with the N flag as you can easily get an infinite recursion.

Answer 2

sedhyphen.sh:

#!/bin/sh
sed -u 's/_/-/g'

httpd conf:

RewriteMap sed-hyphen prg:sedhyphen.sh
RewriteRule ^(.*)$ index.php?/${sed-hyphen:$1} [L]

Make sure that sedhyphen.sh is set executable.

Answer 3

Perhaps this:

RewriteCond %{REQUEST_URI} ^(.*)_(.*)/$
RewriteRule (.*)_(.*)/ http://your-site.com$1-$2/ [R=301]