Apache RewriteRule: it is possible to 'detect' the first and second path segment?

Question

Im really really a newbie in regexp and I can’t figure out how to do that.

My goal is to have the RewriteRule to 'slice' the request URL path in 3 parts:

example.com/foo
#should return: index.php?a=foo&b=&c=

example.com/foo/bar
#should return: index.php?a=foo&b=bar&c=

example.com/foo/bar/baz
#should return: index.php?a=foo&b=bar&c=baz

example.com/foo/bar/baz/bee
#should return: index.php?a=foo&b=bar&c=baz/bee

example.com/foo/bar/baz/bee/apple
#should return: index.php?a=foo&b=bar&c=baz/bee/apple

example.com/foo/bar/baz/bee/apple/and/whatever/else/no/limit/in/those/extra/parameters
#should return: index.php?a=foo&b=bar&c=baz/bee/apple/and/whatever/else/no/limit/in/those/extra/parameters

In short, the first segment in the URL path (foo) should be given to a, the second segment (bar) to b, and the rest of the string in c

I wroted this one

<IfModule mod_rewrite.c>
  RewriteEngine on
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteCond %{REQUEST_URI} !=/favicon.ico
  RewriteRule ^(([a-z0-9/]))?(([a-z0-9/]+))?(([a-z0-9]+))(.*)$ index.php?a=$1&b=$2&c=$3 [L,QSA]
</IfModule>

But obviously doesn’t work, and I don’t even know if what I want is possible.

Any suggestion?

EDIT: After playing with coach manager, I got this one working too:

RewriteRule ^([^/]*)?/?([^/]*)?/?(.*)?$ index.php?a=$1&b=$2&c=$3 [L,QSA]

Answer 1

What about this:

RewriteRule ^/([a-z0-9]+?)(?:/([a-z0-9]+?)){0,1}(?:/(.*)){0,1}$ [L,QSA]

I noticed the following issues with your regex:

• In your first group, you were only looking for the first character - the + sign after the character group states to match the group with any number of characters as long as there's at least one.

• You only need one set of brackets to match the sub-expression

• The ? operator (is this to make the match lazy?) should go straight after the repetition operator (+)

• I also think the request URI starts with /, which was missing from your regex

• Your syntax for the optional groups 2 and 3 wasn't quite correct (?:stuff here){0,1} means that "stuff here" may appear or it may not

I've tested this in a great program called The Regex Coach which gives the following

/foo (or /foo/) = index.php?a=foo&b=&c=
/foo/bar (or /foo/bar/) = index.php?a=foo&b=bar&c=
/foo/bar/any/number/of/other/parameters/after/the/third/one = index.php?a=foo&b=bar&c=any/number/of/other/parameters/after/the/third/one

Answer 2

I would probably use this rule (similar to yours):

RewriteRule ^([^/]+)?/?([^/]+)?/?(.*) index.php?a=$1&b=$2&c=$3 [L,QSA]

And if you don’t want to allow trailing slashes, you can use this rule to remove them:

RewriteRule (.*)/$ /$1 [L,R=301]