Why do two patterns (/.*) and (.*) match different strings?

Question

Shouldn't the two patterns (/.*) and (.*) match the same string? My real question is actually: where did the "abc" go? Something funky seems to be happening inside the mod_rewrite engine...

Given this .htaccess file in www/dir/:

Options +FollowSymlinks
RewriteEngine on
RewriteRule (/.*) print_url_args.php?result=$1

A request for http://localhost/dir/abc/123/ results in:

• result ($1) = "/123/"
• $_REQUEST_URI = "/dir/abc/123/"

If the / is removed from the pattern like RewriteRule (.*) print_url_args.php?result=$1

The same request for 1http://localhost/dir/abc/123/1 results in:

• result ($1) = "print_url_args.php"
• $_REQUEST_URI = "/dir/abc/123/"

---

update: posted rewrite log.

127.0.0.1 - - [15/Feb/2011:14:21:51 +0900] [localhost/sid#1333140][rid#23cd4a8/initial] (3) [perdir C:/db/www/dir/] add path info postfix: C:/db/www/dir/abc -> C:/db/www/dir/abc/123/
127.0.0.1 - - [15/Feb/2011:14:21:51 +0900] [localhost/sid#1333140][rid#23cd4a8/initial] (3) [perdir C:/db/www/dir/] strip per-dir prefix: C:/db/www/dir/abc/123/ -> abc/123/
127.0.0.1 - - [15/Feb/2011:14:21:51 +0900] [localhost/sid#1333140][rid#23cd4a8/initial] (3) [perdir C:/db/www/dir/] applying pattern '(/.*)$' to uri 'abc/123/'
127.0.0.1 - - [15/Feb/2011:14:21:51 +0900] [localhost/sid#1333140][rid#23cd4a8/initial] (2) [perdir C:/db/www/dir/] rewrite 'abc/123/' -> 'print_url_args.php?result=/123/'
127.0.0.1 - - [15/Feb/2011:14:21:51 +0900] [localhost/sid#1333140][rid#23cd4a8/initial] (3) split uri=print_url_args.php?result=/123/ -> uri=print_url_args.php, args=result=/123/
127.0.0.1 - - [15/Feb/2011:14:21:51 +0900] [localhost/sid#1333140][rid#23cd4a8/initial] (3) [perdir C:/db/www/dir/] add per-dir prefix: print_url_args.php -> C:/db/www/dir/print_url_args.php
127.0.0.1 - - [15/Feb/2011:14:21:51 +0900] [localhost/sid#1333140][rid#23cd4a8/initial] (2) [perdir C:/db/www/dir/] strip document_root prefix: C:/db/www/dir/print_url_args.php -> /dir/print_url_args.php
127.0.0.1 - - [15/Feb/2011:14:21:51 +0900] [localhost/sid#1333140][rid#23cd4a8/initial] (1) [perdir C:/db/www/dir/] internal redirect with /dir/print_url_args.php [INTERNAL REDIRECT]
127.0.0.1 - - [15/Feb/2011:14:21:51 +0900] [localhost/sid#1333140][rid#43833c8/initial/redir#1] (3) [perdir C:/db/www/dir/] strip per-dir prefix: C:/db/www/dir/print_url_args.php -> print_url_args.php
127.0.0.1 - - [15/Feb/2011:14:21:51 +0900] [localhost/sid#1333140][rid#43833c8/initial/redir#1] (3) [perdir C:/db/www/dir/] applying pattern '(/.*)$' to uri 'print_url_args.php'
127.0.0.1 - - [15/Feb/2011:14:21:51 +0900] [localhost/sid#1333140][rid#43833c8/initial/redir#1] (1) [perdir C:/db/www/dir/] pass through C:/db/www/dir/print_url_args.php
127.0.0.1 - - [15/Feb/2011:14:24:54 +0900] [localhost/sid#1333140][rid#23bf470/initial] (3) [perdir C:/db/www/dir/] add path info postfix: C:/db/www/dir/abc -> C:/db/www/dir/abc/123/
127.0.0.1 - - [15/Feb/2011:14:24:54 +0900] [localhost/sid#1333140][rid#23bf470/initial] (3) [perdir C:/db/www/dir/] strip per-dir prefix: C:/db/www/dir/abc/123/ -> abc/123/
127.0.0.1 - - [15/Feb/2011:14:24:54 +0900] [localhost/sid#1333140][rid#23bf470/initial] (3) [perdir C:/db/www/dir/] applying pattern '(.*)$' to uri 'abc/123/'
127.0.0.1 - - [15/Feb/2011:14:24:54 +0900] [localhost/sid#1333140][rid#23bf470/initial] (2) [perdir C:/db/www/dir/] rewrite 'abc/123/' -> 'print_url_args.php?result=abc/123/'
127.0.0.1 - - [15/Feb/2011:14:24:54 +0900] [localhost/sid#1333140][rid#23bf470/initial] (3) split uri=print_url_args.php?result=abc/123/ -> uri=print_url_args.php, args=result=abc/123/
127.0.0.1 - - [15/Feb/2011:14:24:54 +0900] [localhost/sid#1333140][rid#23bf470/initial] (3) [perdir C:/db/www/dir/] add per-dir prefix: print_url_args.php -> C:/db/www/dir/print_url_args.php
127.0.0.1 - - [15/Feb/2011:14:24:54 +0900] [localhost/sid#1333140][rid#23bf470/initial] (2) [perdir C:/db/www/dir/] strip document_root prefix: C:/db/www/dir/print_url_args.php -> /dir/print_url_args.php
127.0.0.1 - - [15/Feb/2011:14:24:54 +0900] [localhost/sid#1333140][rid#23bf470/initial] (1) [perdir C:/db/www/dir/] internal redirect with /dir/print_url_args.php [INTERNAL REDIRECT]
127.0.0.1 - - [15/Feb/2011:14:24:54 +0900] [localhost/sid#1333140][rid#23fda10/initial/redir#1] (3) [perdir C:/db/www/dir/] strip per-dir prefix: C:/db/www/dir/print_url_args.php -> print_url_args.php
127.0.0.1 - - [15/Feb/2011:14:24:54 +0900] [localhost/sid#1333140][rid#23fda10/initial/redir#1] (3) [perdir C:/db/www/dir/] applying pattern '(.*)$' to uri 'print_url_args.php'
127.0.0.1 - - [15/Feb/2011:14:24:54 +0900] [localhost/sid#1333140][rid#23fda10/initial/redir#1] (2) [perdir C:/db/www/dir/] rewrite 'print_url_args.php' -> 'print_url_args.php?result=print_url_args.php'
127.0.0.1 - - [15/Feb/2011:14:24:54 +0900] [localhost/sid#1333140][rid#23fda10/initial/redir#1] (3) split uri=print_url_args.php?result=print_url_args.php -> uri=print_url_args.php, args=result=print_url_args.php
127.0.0.1 - - [15/Feb/2011:14:24:54 +0900] [localhost/sid#1333140][rid#23fda10/initial/redir#1] (3) [perdir C:/db/www/dir/] add per-dir prefix: print_url_args.php -> C:/db/www/dir/print_url_args.php
127.0.0.1 - - [15/Feb/2011:14:24:54 +0900] [localhost/sid#1333140][rid#23fda10/initial/redir#1] (1) [perdir C:/db/www/dir/] initial URL equal rewritten URL: C:/db/www/dir/print_url_args.php [IGNORING REWRITE]

Answer 1

When you are in .htaccess context (/.*) will never match the full URL, from the docs:

In Directory and htaccess context, the Pattern will initially be matched against the filesystem path, after removing the prefix that lead the server to the current RewriteRule (e.g. "app1/index.html" or "index.html" depending on where the directives are defined).

and

Per-directory Rewrites

...

The removed prefix always ends with a slash, meaning the matching occurs against a string which never has a leading slash. Therefore, a Pattern with ^/ never matches in per-directory context.

Answer 2

Your question helped me solve a very similar problem!

I don't have access to rewrite logs in my hosting environment (godaddy), so I was totally perplexed by the "second" rewrite, which your logs clearly explain. From there, it wasn't too hard to understand that the key to making this work is that those recursive rewrites have to be stopped somehow.

There's a great solution to that problem here (via serverfault user Dave Drager's answer to a similar question).

Try this:

Options +FollowSymlinks
RewriteEngine on
RewriteCond %{ENV:
REDIRECT_X} =""
RewriteRule (.*) print_url_args.php?result=$1 [E=X:1,L]