I recently migrated a web site from Apache to Nginx (and from CMS-system x to CMS system y)
Almost all of the rewrites are OK in the new CMS, except for one older class of article URLs:
http://example.com/News/Articlepage-News/This-is-the-best-News-EVER.htm (example)

The direct mapping for these literal urls to the new urls is lost.
I do however have a file (200k+ entries) that maps the titles to article-id's like so:
[code]
# old-class-urls.txt: (first two commented lines are not actually in the file)
# all lowercase title without spaces and hyphens article-id
thisisthebestnewsever 123456;
...
[/code]
In apache I used a rewritemap to rewrite these urls:
[code]
# httpd.conf:
...
RewriteMap articles prg:/etc/httpd/rewrites/old-class-article-urls.pl
...
[/code]
[code]
# old-class-article-urls.pl:

#!/usr/bin/perl

$| = 1;

###############################################
# code to be executed at startup of webserver #
###############################################

open(TEXTFILE,"</etc/httpd/rewrites/old-class-urls.txt"); # loading the rewrite map in memory
@lines = <TEXTFILE>;
close TEXTFILE;

foreach $line (@lines) { # load the data in an associative array for fast lookup
($keyword,$article_id) = split(/\s+/,$line);
$keys{$keyword} = $article_id;
}

##########################################
# code to be once every URL is requested #
##########################################

while (<STDIN>) {
$url = $_;
chomp($url);
if($url =~ /\/([^\/]+)\.htm$/) { # a match could be made
$keyword = lc($1);
$keyword =~ s/-//g;
if($keys{$keyword}) {
print 'old-class-url.php?articleid=' . $keys{$keyword}."\n";
next;
}
}
print "Not found\n"; # no match could be made
}
[/code]
I was hoping something similar or even easier could be done with Nginx:

[code]
map $uri $old-class-url {
include /etc/nginx/rewrites/old-class-urls.txt;
}
...
server {
...
location ~* ^/News/Articlepage-News/.*htm {
rewrite ^/News/Articlepage-News/(.*)htm $1 ;
###
### change $uri to lowercase and remove the hyphens...
### I am looking for something equivalent like in perl:
### s/-//g;
### s/.*/\L{$1}/;
###
if ($old-class-url) {
rewrite ^ /old-class-url.php?articleid=$old-class-url permanent;
}
}
}
[/code]

I have seen questions about similar functionality in the forums, but not with a solution:
http://forum.nginx.org/read.php?2,34788
http://forum.nginx.org/read.php?9,2511

Is it possible to solve this issue this way or do you recommend a different solution?

Thanks in advance,
Bart