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--- en:user:gs2_to_gs3 [2026/04/27 22:39] – [Mapping gs2 links into gs3 versions] kjdon
+++ en:user:gs2_to_gs3 [2026/04/30 02:33] (current) – [Extract ids and add as metadata] kjdon
@@ Line 211: / Line 211: @@
 **Scenario:** you have an existing Greenstone 2 collection, with a lot of external sites pointing to documents in it. Eg external databases link to your Greenstone documents.
-The links might look like this: [[http://myserver.com/gsdl/cgi-bin/library.cgi?e=d-01000-00---off-0400years--00-1----0-10-0---0---0direct-10---4-------0-1l--10-hy-50---20-about---00-3-1-00-0--4--0--0-0-11-10-0utfZz-8-00&a=d&c=400years&cl=CL1&d=HASH890dfd99a182f878a55a60]]
+The links might look like this: [[http://myserver.com/greenstone/cgi-bin/library.cgi?e=d-01000-00---off-0400years--00-1----0-10-0---0---0direct-10---4-------0-1l--10-hy-50---20-about---00-3-1-00-0--4--0--0-0-11-10-0utfZz-8-00&a=d&c=400years&cl=CL1&d=HASH890dfd99a182f878a55a60]]
 You want to upgrade your library to Greenstone 3. Now, links to the documents look like this:
@@ Line 218: / Line 218: @@
 Is there a way of automatically mapping the gs2 links into the gs3 collection?
-** Thoughts:**
+==== Part 1: apache rewrite ====
+Edit the apache httpd.conf file to rewrite the requests.
+(If you want to test this out using the apache webserver that came with Greenstone2, add these lines to the end of the file greentone2/apache-httpd/linux/conf/httpd.conf.in - this is a template used to generate the actual runtime version - and then restart apache (gs2-server.sh)
+<code>
+  RewriteEngine On
+  # a test rule to make sure rewriting is working at all - visit localhost:8282/test
+  RewriteRule ^/test$ http://example.com/ [R=302,L]
+  # redirect to Greenstone 3
+  # Match library.cgi requests
+  RewriteCond %{REQUEST_URI} ^/greenstone/cgi-bin/library\.cgi$ [NC]
+  #only a=d versions
+  RewriteCond %{QUERY_STRING} a=d [NC]
+  # Extract collection (c=...) and document (d=...) from query string
+  RewriteCond %{QUERY_STRING} ^.*c=([^&]+).*[&]d=([^&]+).*$ [NC]
+  # the captured groups will be %1 and %2
+  RewriteRule ^/greenstone/cgi-bin/library\.cgi$ https://localhost:8383/greenstone3/library/collection/%1/document/%2? [R=301,L]
+  # optional, if things aren't working, you can log some output to see if matching is happening
+  RewriteLog "/tmp/rewrite.log"
+  RewriteLogLevel 5
+</code>
+Notes:
+  * older versions of Greenstone 2 used gsdl instead of greenstone in URLS, so modify these lines accordingly.
+  * If this apache is not on the same server as the running Greenstone 3, then change localhost:8383 to the public URL of the gs3 library.
+==== Part 2: Get matching doc ids ====
+If you are using HASH ids, then these can change between greenstone versions. Tip - if you want external links into your library, use an OID type that won't change. eg hash_on_full_filename, assigned, filename, dirname, full_filename.
+If the Greenstone 2 used hash ids, when you rebuild in greenstone 3, then hash ids will change. and then the redirects won't work.
+Some options to try:
+=== Don't rebuild ===
+Copy the collection over to greenstone3, open it in GLI to convert the config files - format statements may need tweaking - then see if it works in the library without rebuilding. The HASH ids won't have changed, but whether the collection works properly will depend on the gap between versions. A downside to this way is that you can never rebuild the collection.
+=== Use archives as import ===
+If you have the archives folder available in the greenstone 2 collection, you could use this as the import for the greenstone 3 collection.
+Set up the collection so that it looks right in Greenstone 3 - either by starting from scratch, or by copying over the old collection as above.
+Copy all the HASHxx folders from the greenstone 2 collection's archives folder into the greenstone3 collection's import folder. You don't want archiveinf-* files, rss.items, earliestDatestamp files.
+Then do a full rebuild.
+=== Extract ids and add as metadata ===
+If you no longer have the archives folder in the Greenstone 2 collection, then your task is a bit more complicated.
+What might work is:
+. run db2txt.pl over the gdbm metadata database in the greenstone 2 collection and save to a file, eg: db2txt collect/demo/index/text/demo.gdb > db.out (If the Db is .jdb use jdb2txt.pl instead)
+. Write a script to extract filenames and identifiers from the output. Probably into a CSV file would be easiest:
+<code>
+Filename,prev.Identifier
+sample.pdf,HASH01e86960c45a06eaa801e869
+</code>
+. Put the source documents into the Greenstone 3 collection, add the csv file. Add CSVPlugin to process the csv file. Then use -OIDtype assigned, and -OIDmetadata prev.Identifier import options to get it to use these identifiers as the new doc ids.
+This relies on no subfolders in import.