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| 2 | <head>
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| 3 | <title>Using the Z39.50 Client in Greenstone</title>
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| 4 | </head>
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| 5 |
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| 6 | <body>
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| 7 | <a name=top>
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| 8 | <h1>Using the Z39.50 Client in Greenstone</h1>
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| 9 | </a>
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| 10 | <b>Table of Contents</b><br>
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| 11 | <a href="#whatis">About: What is Z39.50?</a><br>
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| 12 | <a href="#config">Configuring Greenstone - Adding Servers</a><br>
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| 13 | <a href="#todo">Currently known problems, and TODO list</a><br>
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| 14 | <a href="#contact">Contacting Us</a><br>
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| 15 |
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| 16 |
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| 17 |
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| 18 | <a name=whatis>
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| 19 | <h2>What is Z39.50?</h2>
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| 20 | </a>
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| 21 | Z39.50 is an international client/server protocol for searching bibliographic
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| 22 | data. It can use the Internet Protocol (TCP/IP), which makes the databases
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| 23 | on a server available from almost anywhere around the globe. It is widely
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| 24 | used, for example, in on-line library catalogues. It allows a user to search
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| 25 | one or more databases and retrieve the results of the query.
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| 26 |
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| 27 | <p>
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| 28 | Our implementation uses the YAZ z39.50 toolkit, written by
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| 29 | <a href="http://www.indexdata.dk">Index Data</a>.
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| 30 |
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| 31 |
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| 32 |
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| 33 | <a name=config>
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| 34 | <h2>Adding Servers</h2>
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| 35 | </a>
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| 36 | The file z3950.cfg in the etc/packages directory contains entries for
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| 37 | each server. By default, no servers are set up, although the config file
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| 38 | comes with two (commented out) example Z39.50 servers, both for servers
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| 39 | of the United States' <b>Library of Congress</b>.
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| 40 | <p>
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| 41 | Each entry consists of:
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| 42 | <ul>
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| 43 | <li>A unique "short name" for internal use by Greenstone.</li>
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| 44 | <li>The internet name or address of the server, and optionally the
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| 45 | port that the server is running on if not the default port 210.</li>
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| 46 | <li>The name of the database to search on that server.</li>
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| 47 | <li>A string that provides a meaningful name for the "collection".</li>
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| 48 | <li>An optional "About" string, providing some information about the database
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| 49 | and/or server.</li>
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| 50 | <li>Optional icon fields, which are displayed instead of the text on the
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| 51 | front page.</li>
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| 52 | </ul>
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| 53 | The entries need only be separated by whitespace, but for the purposes of
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| 54 | clarity the sample entry uses newlines and tabs.
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| 55 | <p>
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| 56 | The sample Library of Congress entry looks like this:
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| 57 | <pre>
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| 58 | LOC
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| 59 | z3950.loc.gov:7090
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| 60 | Voyager
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| 61 | "Library of Congress z39.50 server"
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| 62 | About en "This is the z39.50 interface to the US LoC catalogue
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| 63 | system. It contains approximately 12 million bibliographic records.
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| 64 | For server capabilities, look at
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| 65 | <a href=\"http://lcweb.loc.gov/z3950/lcserver.html\">their web pages</a>."
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| 66 | </pre>
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| 67 | There is a list at the Library Of Congress website containing some
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| 68 | <a href="http://lcweb.loc.gov/z3950/agency/resources/testport.html">servers
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| 69 | publicly available for testing</a>.
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| 70 |
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| 71 |
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| 72 | <a name=todo>
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| 73 | <h2>Known Problems/Issues list</h2>
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| 74 | </a>
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| 75 | <ul>
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| 76 | <li>Because of the open nature of the standard, our client may not work with
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| 77 | some servers. Please notify the author (contact details below) of any
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| 78 | such problems.</li>
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| 79 | <li>Because of the large number of Marc fields, only the most frequently
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| 80 | used fields have been given explicit names in the results. Furthermore,
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| 81 | these are currently hard-coded to correspond to the USMARC field names.</li>
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| 82 | <li><b>The z39.50 client will not work when fast-cgi is used!</b>. Currently,
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| 83 | the use of the fast-cgi package (off by default) will disable the
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| 84 | use of the z39.50 client code for Greenstone.</li>
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| 85 | <li>There are spurious <B> tags in the title of the window when
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| 86 | viewing an individual record.</li>
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| 87 | <li>Greenstone will claim there are no collections if there are no
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| 88 | sub-directories in the "collect" directory, even if there are configured
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| 89 | z39.50 servers, although it will work if there are unbuilt collections.</li>
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| 90 | </ul>
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| 91 |
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| 92 | <b>History</b><br>
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| 93 | Jul 2001 - finally tracked down and fixed an annoying bug that caused
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| 94 | greenstone to segfault when retrieving documents for some queries.<br>
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| 95 | Jun 2001 - decided to drop href for field 856, as some examples have
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| 96 | explanatory text in the field as well as the URI.<br>
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| 97 | Oct 2000 - cache results from server, so cut down the number of connections for
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| 98 | a single query/document. Also added href for MARC field 856.<br>
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| 99 | Aug 2000 - Various bug fixes and minor modifications.<br>
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| 100 | Fri Aug 4 2000 - The z39.50 code is now "stable" in the main source code (in CVS).<br>
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| 101 | Tue 1 Aug 2000 - selecting a field from the drop-down box now actually works.
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| 102 | This results in both quicker replies and more accurate results.<br>
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| 103 | Mon 24 Jul 2000 - queries are now "AND"ed - for example, the query "computer
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| 104 | science" will now only return records that contain both words.<br>
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| 105 | May-June 2000 - Code written.<br>
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| 106 |
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| 107 | <a name=contact>
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| 108 | <h2>Contact Details</h2>
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| 109 | </a>
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| 110 | For general comments about Greenstone, or suggestions for improvements, send
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| 111 | email to
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| 112 | <a href="mailto:[email protected]?subject=z39.50 client in Greenstone">[email protected]</a><br>
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| 113 | <br>
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| 114 | For bug reports or questions about the z39.50 code itself, send email to
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| 115 | the author, John McPherson -
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| 116 | <a href="mailto:[email protected]?subject=z39.50 client in Greenstone"
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| 117 | >[email protected]</a>.
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| 118 |
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| 119 | <p>
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| 120 | <a href="#top">Back to top</a>
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| 121 | <p>
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| 122 | <address>Last modified: July 12, 2001 by John McPherson</address>
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| 123 | </body>
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| 124 | </html>
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