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Grex > Web > #8: An Exercise in URL Rewriting | |
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| Author |
Message |
| 8 new of 11 responses total. |
remmers
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response 4 of 11:
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Mar 9 22:15 UTC 2007 |
Hm... In testing the link in resp:3, it seems that no referer header is
sent, at least by my browser (Safari). However, I made a page
http://grex.org/~remmers/referer.html that links to c2.com/cgi/test/;
when I click on *that* link, Safari sends the expected referer header.
Same results with Firefox.
Not sure what's going on. If I click on the link in resp:3 from my usual
Backtalk interface (pistachio), no referer is sent. However, it is from
the vanilla interface.
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cmcgee
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response 5 of 11:
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Mar 10 13:42 UTC 2007 |
John, I'm reading, even if it's mostly over my head. Thank you for musing
outloud about this stuff.
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remmers
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response 6 of 11:
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Mar 10 14:05 UTC 2007 |
You're welcome.
Okay, a little more investigation seems to indicate that a referer is sent
if you're using Backtalk in readonly mode and not if you're using it as an
authenticated user. Maybe it's a security feature.
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remmers
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response 7 of 11:
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Mar 10 15:05 UTC 2007 |
Getting back to the original topic, here are the details on how the URL
rewriting is done. In the root web directory of my website, I created a
directory called "grex" and a subdirectory of that called "bbs" (which
you can see via the link http://jremmers.org/grex/).
The only file in the bbs directory is a .htaccess file that specifies
how anything following "grex/" is translated. (The line numbers are
supplied for ease of reference and aren't actually part of the file.
Also, for readability I've done some line wrapping; each number
corresponds to one line of the file. You can see the actual .htaccess
file at http://jremmers.org/htaccess-example.txt)
-----------------------------------------------------------------------
1. RewriteEngine
on
2. RewriteRule
^/*$
http://grex.org/cgi-bin/backtalk/vanilla/conflist
3. RewriteRule
^([^/]+)/*$
http://grex.org/cgi-bin/backtalk/vanilla/browse?conf=$1
4. RewriteRule
^([^/]+)/+([0-9]+)/*$
http://grex.org/cgi-bin/backtalk/vanilla/read?conf=$1&item=
$2&rsel=all
5. RewriteRule ^([^/]+)/+([0-9]+)/([^/]+)/*$ http://grex.org/cgi-bin
/backtalk/vanilla/read?conf=$1&item=$2&rsel=$3
----------------------------------------------------------------------
Line 1 tells Apache to pay attention to the rewriting rules.
The next 4 lines are rewriting rules, each of the form
RewriteRule PATTERN REPLACEMENT
The PATTERN is a "regular expression" that specifies the form of what is
to be replaced. The REPLACEMENT is what to replace anything with that
matches the pattern. I won't attempt to explain regular expressions in
general here (see Google or Wikipedia), but for example the regular
expression "^([^/]+)/*$" matches any string of one or more non-slash
characters, followed by 0 or more slashes. The parentheses around
"[^/]+" tells the rewrite engine to store the string of non-slashes in a
variable named "$1" which can then be referenced in the replacement.
For example, in the URL "http://jremmers.org/grex/bbs/coop", the string
"coop" matches the string-of-non-slashes expression "[^/]+". Since the
latter is parenthesized, it's stored as "$1" and then dumped into the
corresponding replacement. The rewritten URL is thus
http://grex.org/cgi-bin/backtalk/vanilla/browse?conf=coop
which is a standard Backtalk URL for generating the index to a
conference.
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remmers
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response 8 of 11:
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Mar 10 15:16 UTC 2007 |
Late-breaking news: I created a .htaccess file in the above-mentioned
"grex" directory that makes the browsing scheme a little more
hierarchical; the URL "http://jremmers.org/grex" takes you to the Grex
homepage.
Exercise for the technically inclined: What .htaccess file would achieve
this effect?
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fuzzball
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response 9 of 11:
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Mar 23 15:51 UTC 2007 |
very nice john....
wouldent have thought of doing this.....
:)
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remmers
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response 10 of 11:
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Mar 24 13:05 UTC 2007 |
What led me to do this is some recent reading about "well-designed URLs".
This got me to thinking about what a simple, clean, human-friendly URL
scheme for bbs items and responses might look like.
For some good ideas on the issue of well-designed URLs, see Mike
Schinkel's post
http://www.mikeschinkel.com/blog/welldesignedurlsarebeautiful/
and the various references he gives.
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madmike
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response 11 of 11:
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Sep 26 16:04 UTC 2008 |
Very good stuff. Thanks for the link to mikeschinkel.com. I will have
to mess around with this.
Isn't .htaccess strictly an Apache thing, or is it also supported by
the Windows server platforms?
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