.htaccess mod_rewrite

[xmrjustin]

I am attempting to use .htaccess to modify URLs/URL variables for seo purposes.  Specifically, I am trying to rewrite:

http://host.com/variable1/variable2.cfm

to

http://host.com/variable1.cfm?id=variable2

Unfortunately, I am failing miserably.  The following is what I have so far, and I am stuck.  Any suggestions that you could provide would be greatly appreciated.

Options +FollowSymLinks
RewriteEngine on
RewriteBase /
RewriteRule /(.*)/(.*) /$1.cfm\?id=$2 [I,O]

[TLC-IT · Accepted solution]

Your problem is undoubtedly in the pattern portion of your rewrite-rule.

Remember that regular-expression patterns can be "greedy" or "non-greedy,"which means that they can either seek to match the largest possible substring or the smallest one.

For example, ponder the potential differences that can occur when munching on "http://my.web.site/parm1/parm2/parm3" against a pattern of "(.*)/(.*)"  Your expectation of what will happen is probably "non-greedy."  But the bottom line is, "your expectations" don't mean squat.   Or rather, they amount to a huge waste of time and hair.  What you need to know, is to know.  And there's really only one way to find out  . . .

There are plenty of "try a regular expression" web-sites out there, where you can actually type-in a regex and a string and see what is or isn't matched.  Everyone (including both Apache and ColdFusion nee Java) uses compatible regular-expression engines these days, so you can pretty much "take your pick" of sites.

Regular expressions are always a surprise, but especially so when you start using constructs like ".*"  Save your hair-follicles and try it.

(I also do not see documentation of the 'I' and 'O' flags of RewriteRule.)

[Adam Cameron.]

It might be good to ask this on an Apache forum, given it's an Apache question.

One handy tool to get hold of when testing regexes is Regex Coach: http://weitz.de/regex-coach/

Also - I'm running from memory here - isn't there a way to log what Apache is doing when it's performing mod-rewrite operations so you can see where you're going wrong?  Or perhaps I'm thinking of IIS..?

Looking at your regex, the second sub-expression will also grab the ".cfm" part of the URL, won't it?  You don't want that: you want everything up to the ".cfm" in your sub-expression.

--

Adam