causing headache in RewriteRule - regex

I am struggling with a very basic regex problem in my .htaccess file that I hope someone may be able to shed some light on. The basic premise is that I would like to teach Apache to switch any .html extension into a .var extension. I had thought that the rule would be positively trivial:
RewriteRule ^([^.]+)\.html$ $1.var
But the [^.] part simply doesn't work. Bizarrely, it works like so
RewriteRule ^([^A-Z]+)\.html$ $1.var
I do not understand why this latter rule works. Assume I am looking for a file called "index.html" then $1 should match to "index." and the ".html" bit should actually fail to match.
To widen the scope of the question slightly, I am actually racking my brain on how to implement a multi-lingual site. I don't like Apache's MultiView option because it forces upon me a flat directory structure with file extensions that aren't recognizable to many development tools. I could go the .var type-map route but am finding that the default config for Apache doesn't support this all that well either (hence my excursions into regex land). So while I am using mod_rewrite, I am thinking that I might go the whole hog: whenever a request for a name.html file is received and this file does not exist, check whether there exists a XX/name.html file instead, where "XX" is the language code according to the user's preferences.
This would give me a neater directory structure, though it does perhaps not perform as well as the .var approach in a situation where the language preference of the user's browser is not supported in by my site (in which situation .var would substitute EN or similar).
Any thoughts? Thanks.

Why don't you just use ^(.*)\.html$? This will match any string that ends in .html. After all, filenames can contain more than one dot.
[^A-Z]+ matches index if the regex is applied case-sensitively. Perhaps that's the reason? Why [^.]+ should fail is beyond me, though.

The . matches everything but newlines.
Inside of a character class, the ^ means "not".
The + means one or more of the preceding character class.
So when you write ([^.]+), that says "match one or more newlines". So unless you have a URL composed of newlines followed by ".html", this will not work.
^([^A-Z]+)\.html$ works because it matches one or more characters that are not uppercase letters. If you have any uppercase letters before the ".html" in your URL, this one will fail too.
Tim Pietzcker's suggestion is correct: just use ^(.*)\.html$,keeping in mind that this won't work in the odd case that you have newlines in your URL.
In the odd case that you actually have URL's with newlines in them, you can use ^([\d\D]+)\.html$, which will match digits and non-digits (i.e. everything) up until the ".html".

Related

How to only show id value on url path with htaccess?

What I have right now is
https://www.example.com/link.php?link=48k4E8jrdh
What I want to accomplish is to get this URL instead =
https://www.example.com/48k4E8jrdh
I looked on the internet but with no success :(
Could someone help me and explain how this works?
This is what I have right now (Am I in the right direction?)
RewriteEngine On
RewriteRule ^([^/]*)$ /link.php?link=$1
RewriteRule ^([^/]*)$ /link.php?link=$1
This is close, except that it will also match /link.php (the URL being rewritten to) so will result in an endless rewrite-loop (500 Internal Server Error response back to the browser).
You could avoid this loop by simply making the regex more restrictive. Instead of matching anything except a slash (ie. [^/]), you could match anything except a slash and a dot, so it won't match the dot in link.php, and any other static resources for that matter.
For example:
RewriteRule ^([^/.]*)$ link.php?link=$1 [L]
You should include the L flag if this is intended to be the last rule. Strictly speaking you don't need it if it is already the last rule, but otherwise if you add more directives you'll need to remember to add it!
If the id in the URL should only consist of lowercase letters and digits, as in your example, then consider just matching what is needed (eg. [a-z0-9]). Generally, the regex should be as restrictive as required. Also, how many characters are you expecting? Currently you allow from nothing to "unlimited" length.
Just in case it's not clear, you do still need to change the actual URLs you are linking to in your application to be of the canonical form. ie. https://www.example.com/48k4E8jrdh.
UPDATE:
It works but now the site always sees that page regardless if it is link.php or not? So what happens now is this: example.com/idu33d3dh#dj3d3j And if I just do this: example.com then it keeps coming back to link.php
This is because the regex ^([^/.]*)$ matches 0 or more characters (denoted by the * quantifier). You probably want to match at least one (or some minimum) of character(s)? For example, to match between 1 and 32 characters change the quantifier from * to {1,32}. ie. ^([^/.]{1,32})$.
Incidentally, the fragment identifier (fragid) (ie. everything after the #) is not passed to the server so this does not affect the regex used (server-side). The fragid is only used by client-side code (JavaScript and HTML) so is not strictly part of the link value.

More efficient RewriteRule for messy URL

I have developed a new web site to replace an existing one for a client. Their previous site had some pretty nasty looking URLs to their products. For example, an old URL:
http://mydomain.com/p/-3-0-Some-Ugly-Product-Info-With-1-3pt-/a-arbitrary-folder/-18pt/-1-8pt-/ABC1234
I want to catch all requests to the new site that use these old URLs. The information I need out of the old URL is the ABC1234 which is the product ID. To clarify, the old URL begins with /p/ followed by four levels of folders, then the product ID.
So for example, the above URL needs to get rewritten to this:
http://mydomain.com/shop/?sku=ABC1234
I'm using Apache 2.2 on Linux. Can anyone point me on the correct pattern to match? I know this is wrong, but here is where I am currently at:
RewriteRule ^p/([A-Za-z0-9-]+)/([A-Za-z0-9-]+)/([A-Za-z0-9-]+)/([A-Za-z0-9-]+)/([A-Za-z0-9-]+)?$ shop/?sku=$5 [R=301,NC,L]
I'm pretty sure that the pattern used to match each of the 4 folders is redundant, but I'm just not that sharp with regex. I've tried some online regex evaluators with no success.
Thank you.
--EDIT #1--
Actually, my RewriteRule above does work, but is there a way to shorten it up?
--EDIT #2--
Thanks to ddr, I've been able to get this expression down to this:
RewriteRule ^p/([\w-]+/){4}([\w-]+)$ shop/?_sku=$2 [R=301,NC,L]
--EDIT #3--
Mostly for the benefit of ddr, but I welcome anyone to assist who can. I'm dealing with over 10,000 URLs that need to be rewritten to work with a new site. The information I've provided so far still stands, but now that I am testing that all of the old URLs are being rewritten properly I am running into a few anomolies that don't work with the RewriteRule example provided by ddr.
The old URLs are consistent in that the product ID I need is at the very end of the URL as documented above. The first folder is always /p/. The problem I am running into at this point is that some of the URLs have a URL encoded double quote ("). Additionally, some of the URLs contain a /-/ as one of the four folders mentioned. So here are some examples of the variations in the old URLs:
/p/-letters-numbers-hyphens-88/another-folder/-and-another-/another-18/ABC1234
/p/-letters-numbers-hyphens-88/2%22/-/-/ABCD1234
/p/letters-numbers-hyphens-1234/34-88/-22/-/ABCD1234/
Though the old URLs are nasty, I think it is safe to say that the following are always true:
Each begins with /p/
Each ends with the product ID that I need to isolate.
There are always four levels of folders between /p/ and the product ID.
Some folders in between have hyphens, some don't.
Some folders in between are a hyphen ONLY.
Some folders in between contain a % character where they are URL encoded.
Some requests include a / at the very end and some do not.
The following rule was provided by ddr and worked great until I ran into the URLs that contain a % percent sign or a folder with only a hyphen:
RewriteRule ^p/(?:[\w-]+/){4}([\w-]+)$ shop/?_sku=$1 [R=301,NC,L]
Given the rule above, how do I edit it to allow for a folder that is hyphen only (/-/) or for a percent sign?
You can use character classes to reduce some of the length. The parentheses (capture groups) are also unnecessary, except the last one, as #jpmc26 says.
I'm not especially familiar with Apache rules, but try this:
RewriteRule ^p/(?:[\w-]+/){4}([\w-]+)$ shop/?sku=$1 [R=301,NC,L]
It should work if extended regular expressions are supported.
\w is equivalent to [A-Za-z0-9_] and you don't need to not capture underscores, so that's one replacement.
The {4} matches exactly four repetitions of the previous group. This is not always supported so Apache may not like it.
The ?: is optional but indicates that these parens should not be treated as a capture. Makes it slightly more efficient.
I'm not sure what the part in [] at the end is for but I left it. I can't see why you'd need a ? before the $, so I took it out.
Edit: the most compact way, if Apache likes it, would probably be
RewriteRule ^p(/[\w-]+){5}$ shop/?sku=$5 [R=301,NC,L]
EDIT: response to edit 3 of the question.
I'm surprised it doesn't work with only -. The [\w-]+ should match even where there is just a single -. Are you sure there isn't something else going on in these URLs?
You might also try replacing - in the regex with \-.
As for the %, just change [\w-] to [\w%-]. Make sure you leave the - at the end! Otherwise the regex engine will try to interpret it as part of a char sequence.
EDIT 2: Or try this:
RewriteRule ^p/(?:.*?/){4}(.*?)/?$ shop/?sku=$1 [R=301,NC,L]

regex, find last part of a url

Let's take an url like
www.url.com/some_thing/random_numbers_letters_everything_possible/set_of_random_characters_everything_possible.randomextension
If I want to capture "set_of_random_characters_everything_possible.randomextension" will [^/\n]+$work? (solution taken from Trying to get the last part of a URL with Regex)
My question is: what does the "\n" part mean (it works even without it)? And, is it secure if the url has the most casual combination of characters apart "/"?
First, please note that www.url.com/some_thing/random_numbers_letters_everything_possible/set_of_random_characters_everything_possible.randomextension is not a URL without a scheme like http:// in front of it.
Second, don't parse URLs yourself. What language are you using? You probably don't want to use a regex, but rather an existing module that has already been written, tested, and debugged.
If you're using PHP, you want the parse_url function.
If you're using Perl, you want the URI module.
Have a look at this explanation: http://regex101.com/r/jG2jN7
Basically what is going on here is "match any character besides slash and new line, infinite to 1 times". People insert \r\n into negated char classes because in some programs a negated character class will match anything besides what has been inserted into it. So [^/] would in that case match new lines.
For example, if there was a line break in your text, you would not get the data after the linebreak.
This is however not true in your case. You need to use the s-flag (PCRE_DOTALL) for this behavior.
TL;DR: You can leave it or remove it, it wont matter.
Ask away if anything is unclear or I've explained it a little sloppy.

Regex with special characters

I am using some url rewriting for a site I am currently working on. I have the rewriting working fine for numbers, letters and - using this:
RewriteRule ^([a-zA-Z0-9_-]+)/([a-zA-Z0-9_-]+)$ characters.php?realm=$1&name=$2 [NC]
However I need the first part of the rule to allow for ' to be allowed, and I need the second part of the rule to allow for special characters such as ú, æ, ä, ç, and pretty much all of the characters located here that resemble a letter.
I know special characters are bad, but I am not the one that allowed them to be used in character names. I just need them to be allowed in my rule so that the characters with those names can access my application.
Thanks.
Edit: The first part works now. Experimenting with the second part at the moment.
Edit #2: Trying both solutions for the second part ([^/]+) and excluding certain characters allows for the information to display instead of resulting in a 404 error. However it is causing my CSS to not be displayed, instead it is trying to call /css/error instead of /css. It is causing a redirect loop for the css file according to chrome.
The only way something should be redirected to /error is if the character data is invalid. This application is being used to pull character information from the blizzard character api, so it is essential that the accented characters can be used in the rewriting.
I'm not sure if this is important or not, but when I to allow for just ú to be included along with a-z and A-Z I get a 404 error stating that the page cannot be found but instead of displaying the ú it displays ú in its place.
^([a-zA-Z0-9_'-]+)/([^excluded characters here]+)$
adding the "'" inside the first brackets should allow it to be matched. As far as the second goes, you may want to use a negated character class, and list the characters that you do not allow.
edited to move the single quote before the "-".
Simplest solution I could come up with is that ú displays as ú for example, so I just simply included the ú in the rule. Not sure if it is the best way, but it works for now.

RegEx match replace help

I am trying to do a regex match and replace for an .htaccess file but I can't quite figure out the replace bit. I think I have the match part right, but maybe someone can help.
I have this url-
http://www.foo.com/MountainCommunities/Lifestyles/5/VacationHomeRentals.aspx
And I'm trying to turn it into this-
http://www.foo.com/mountain-lifestyle/Vacation-Home-Rentals.aspx
(MountainCommunities/Lifestyles)/\d/(.*)(.aspx)
and then I figured I would have a rewrite rule starting like this-
mountain-lifestyle/$2$3
but I need to take what is in $2 in this instance and rewrite it to place dashes between the words with capital letters. Now I'm stumped.
I think you'll have to do it in two bits... Take out $2, precede every capital (apart from the first) with a -, then use just append the result to http://www.foo.com/mountain-lifestyle/ with a .aspx on the end.
Try this:
RewriteRule ^(([A-Z][a-z]+-)*)([A-Z][a-z]+)(([A-Z][a-z]+)+)(\.aspx)?$ /$1$3-$4 [N]
RewriteRule ^([A-Z][a-z]+-)+[A-Z][a-z]+$ /$0.aspx [R=301]
Note that mod_rewrite uses an internal counter to detect and avoid infinit loops. So your URL may not contain too much words having to be converted (see MaxRedirects option for Apache < 2.1 and LimitInternalRecursion directive for Apache ≥ 2.1).
I don't think what your doing with the capital letters is possible with regex...
You would be better keeping the dashes in the URL and removing the .aspx
eg: http://www.foo.com/MountainCommunities/Lifestyles/5/Vacation-Home-Rentals
This would require the following rule:
^/MountainCommunities/Lifestyles/5/([^/]+)/\?([^/]+) /mountain-lifestyle/$1.aspx?$2 [I]
This also takes into account any querystrings that are sent to the page.
BTW: How are you using .htaccess with IIS?
You can use the regular expression "([A-Z])" on the middle bit "VacationHome", replacing with the regex "-$1" - This will give you "-Vacation-Home-Rentals" - Then you can just chop off the first character, and stick the first part of the URL on the front, and .aspx on the end.
I think the main regex has been written by others, but to match the request name to place dashes (assuming all the file names have a three-name camel cased representation ala 'VacationHomeRentals.aspx':
RewriteRule: ^/MountainCommunities/Lifestyles/\d+/([A-Z][a-z]+)([A-Z][a-z]+)([A-Z][a-z]+)\.aspx$ /mountain-lifestyle/$1-$2-$3.aspx
This is a restricted version of #Gumbo's response, as I have not had a chance to test his recursion. The recursion technique is definitely the best and most usable for any scenario.
I don't think I quite understand what you are trying to do. Why can't you simply search for:
http://www.foo.com/MountainCommunities/Lifestyles/5/VacationHomeRentals.aspx
and replace it with:
http://www.foo.com/mountain-lifestyle/Vacation-Home-Rentals.aspx ?
Or is this a specific example of a patten you are trying to transform?