URL Rewriter Help
Table of contents
What is URL Rewriter?
URL Rewriter is an extension for Pale Moon that allows you to automatically redirect from
one webpage to another. For example, every time you visit http://abc.com you will automatically
load http://def.com instead. This can be useful for instance to always redirect articles to printer friendly
versions, redirect http:// to https:// for sites that support both, bypass advertising pages that appear before
being able to view certain pages and more.
Basic usage
To add a new redirect you can go to the Tools menuitem and select URL Rewriter. That will
open the URL Rewriter settings window which shows all your redirects. The window can also be opened
by right clicking on the R icon in your statusbar.
There you can press the Add... button and then you can enter the details for the new redirect. A redirect
consists of a few things:
- Example url: This is an example of an url you want to redirect. It is not really used for anything,
it's just there to show what types of urls you're targetting. You can leave this out, but then you can't use the Test pattern button.
- Include pattern: This is pattern for the urls you want to redirect. In the simplest case, where you just want
to redirect one specific url to another then this will just be the exact url you want to redirect. For instance, if you just want http://aaa.com to
redirect to http://bbb.com then Include pattern will just be http://aaa.com. For more complex patterns that match many
urls you can use either wildcards or regular expressions.
- Exclude pattern: Urls that match this pattern will never be redirected. This is not necessary to
fill out, but can be useful when you want to redirect all urls that contain some text except if they contain some other text.
Redirects like that can often be done with a complex regular expression, but using an exclude pattern makes it much simpler. The exclude
patterns can use wildcard characters or regular expressions like the include patterns.
- Redirect to: This is the url that you will be redirected to when you open any page where the url matches the
include pattern. You can use the special signs $1, $2, $3 etc. in the url, they will be replaced by the results of captures with regular
expressions or stars with wildcards. For instance, if you have the include pattern http://google.com/*, redirect to http://froogle.com/$1
and you open the page http://google.com/foobar, then you will be redireced to http://froogle.com/foobar, since 'foobar' was what the star replaced. $1 is for the
first star in the pattern, $2 for the second and so on. For regular expression $1 is for the first parantheses, $2 for the second etc.
- Pattern type: This specifies how URL Rewriter should interpret the patterns, either as
wildcards or regular expressions.
- Unescape matches: A common usage of URL Rewriter is to catch urls like
http://foo.com/redirect.php?url=http%3A%2F%2Fbar%2Ecom%2Fpath and try to catch the url parameter and redirect to it. A pattern
like http://foo.com/redirect.php?url=* might be used for that purpose. However, if the url parameter is escaped (also known
as urlencoded) then that won't work. In the url above we see that it starts with http%3A%2F%2F instead of http://, and Pale Moon
won't accept this as a new url to redirect to. So, in cases like these you can check the Unescape matches option and then all
matches will be unescaped (turned from e.g. http%3A%2F%2Fbar%2Ecom to http://bar.com) before being inserted into the target url.
Wildcards
Wildcards are the simplest way to specify include and exclude patterns. When you create a wildcard pattern there
is just one special character, the asterisk *. An asterisk in your pattern will match zero or more characters and you can
have more than one star in your pattern. Some examples:
- http://example.com/* matches http://example.com/, http://example.com/foo, http://example.com/bar and all other urls that start with http://example.com/.
- http://*.example.com matches all subdomains of example.com, like http://www.example.com, http://mail.example.com.
- http*://example.com matches both http://example.com and https://example.com.
- http://example.com/index.asp* matches http://example.com/index.asp, http://example.com/index.asp?a=b&c=d.
$1, $2, $3 in the redirect urls will match the text that the stars matched. Examples:
- http://example.com/* matches http://example.com/foobar, $1 is foobar.
- http://*.example.com/* matches http://www.example.com/foobar, $1 is www, $2 is foobar.
Regular expressions
Regular expressions allow for more complicated patterns but they are a lot harder to learn than wildcards. I'm not gonna
create a regex tutorial here but normal javascript regex syntax works, look at http://regular-expressions.info for
an introduction to regular expressions. $1,$2 etc. can be used in the redirect url and will be replaced with contents of captures in
the regular expressions. Captures are specified with parantheses. Example: http://example.com/index.asp\?id=(\d+) will match the url
http://example.com/index.asp?id=12345 and $1 will be replaced by 12345. (A common mistake in regex patterns is to forget to escape
the ? sign in the querystring of the url. ? is a special character in regular expressions so if you want to match an url with a querystring
you should escape it as \?).
Examples
-
Static redirect
Redirects from http://example.com/foo to http://example.com/bar
Include pattern: http://example.com/foo
Exclude pattern:
Redirect to: http://example.com/bar
Pattern type: Wildcard
-
Redirect using query string parameter and wildcards
Redirects from http://example.com/index.php?id=12345&a=b to http://example.com/printerfriendly.php?id=12345&a=b
where 12345 could be any number.
Include pattern: http://example.com/index.php?id=*&a=b
Exclude pattern:
Redirect to: http://example.com/printerfriendly.com?id=$1&a=b
Pattern type: Wildcard
-
Redirect using query string parameter and regular expressions
Redirects from http://example.com/index.php?id=12345&a=b to http://example.com/printerfriendly.php?id=12345&a=b
where 12345 could be any number.
Include pattern: http://example.com/index.php\?id=(\d+)&a=b
Exclude pattern:
Redirect to: http://example.com/printerfriendly.com?id=$1&a=b
Pattern type: Regular Expression
-
Redirect to a different folder using wildcards
Redirects from http://example.com/category/fish/index.php to http://example.com/category/cats/index.php
where fish could be any word. The exclude pattern makes sure that there is only one
folder there, so for instance http://example.com/category/fish/cat/mouse/index.php would not match.
Include pattern: http://example.com/category/*/index.php
Exclude pattern: http://example.com/category/*/*/index.php
Redirect to: http://example.com/category/cats/index.php
Pattern type: Wildcard
-
Redirect http to https using wildcards
Redirects from http://mail.google.com/randomcharacters to https://mail.google.com/randomcharacters
where randomcharacters could be anything.
Include pattern: http://mail.google.com*
Exclude pattern:
Redirect to: https://mail.google.com$1
Pattern type: Wildcard