Forum und email

YAZ Functions

Introducere

This extension offers a PHP interface to the YAZ toolkit that implements the » Z39.50 Protocol for Information Retrieval. With this extension you can easily implement a Z39.50 origin (client) that searches or scans Z39.50 targets (servers) in parallel.

The module hides most of the complexity of Z39.50 so it should be fairly easy to use. It supports persistent stateless connections very similar to those offered by the various RDB APIs that are available for PHP. This means that sessions are stateless but shared among users, thus saving the connect and initialize phase steps in most cases.

YAZ is available at » https://www.indexdata.dk/yaz/. You can find news information, example scripts, etc. for this extension at » https://www.indexdata.dk/phpyaz/.

Notă: Această extensie a fost transferată în repozitoriul » PECL şi nu mai este furnizată împreună cu PHP începând cu versiunea 5.0.0.

Instalarea

Obtain YAZ (ANSI/NISO Z39.50 support) and install it. YAZ can be fetched in source or in various prebuilt packages from the » YAZ archive. Systems such as Debian GNU/Linux, Suse Linux, FreeBSD also has YAZ as part of their distribution.

For the PHP 4 series, the YAZ extension is bundled (but not YAZ itself) Build PHP with your favorite modules and add option --with-yaz[=DIR].

Example#1 YAZ compilation for PHP 4 on Unix

gunzip -c php-4.4.X.tar.gz|tar xf -
gunzip -c yaz-2.1.8.tar.gz|tar xf -
cd yaz-2.1.8
./configure --prefix=/usr
make
sudo make install
cd ../php-4.4.X.
./configure --with-yaz=/usr/bin
make
sudo make install

For PHP 5, the YAZ extension is in » PECL and is installed as a shared object/dll. If you have pear installed the easiest way to download, configure and install the YAZ extension is by using the pecl command.

Installation of YAZ on Linux

Informaţie despre instalarea acestei extensii PECL poate fi găsită în capitolul manualului, întitulat Instalarea extensiilor PECL. Informaţii adiţionale, cum ar fi lansări noi, descărcări, fişiere-sursă, informaţii despre persoana care întreţine extensia şi istoria schimbărilor poate fi localizată aici: » https://pecl.php.net/package/yaz

Installation on Windows systems

Biblioteca DLL pentru această extensie PECL poate fi descărcată de pe pagina » PHP Downloads sau de pe » https://pecl4win.php.net/ php_yaz.dll depends on yaz.dll. The yaz.dll is part of the Win32 ZIP from the PHP site. It is also part of the Windows YAZ install available from the » YAZ WIN32 area.

Avertizare

The PHP 5.0.5 Win32 zip includes a too old version of yaz.dll (version 1.9.1 < required version 2.0.13). If that's the case use the yaz.dll from a newer » YAZ WIN32 install.

On windows, don't forget to add the PHP directory to the PATH, so that the yaz.dll file can be found by the system.

If you are using YAZ as a shared extension, add (or uncomment) the following line in php.ini on Unix:

   extension=yaz.so
  
And for Windows:
   extension=php_yaz.dll
  

Avertizare

Extensiile IMAP, recode, YAZ şi Cyrus nu pot fi utilizate împreună, deoarece ele utilizează acelaşi simbol intern.

Notă: The above problem is solved in version 2.0 of YAZ.

Configuraţia la rulare

Comportamentul acestor funcţii este afectat de parametrii stabiliţi în php.ini.

YAZ configuration options
Name Default Changeable Changelog
yaz.max_links "100" PHP_INI_ALL Available since PHP 4.3.0. Removed in PHP 5.0.0.
yaz.log_file NULL PHP_INI_ALL Available since PHP 4.3.0. Removed in PHP 5.0.0.
Pentru mai multe detalii şi definiţii ale constantelor PHP_INI_* accesaţi php.ini directives.

Tipurile resurselor

Această extensie nu are tipuri de resurse definite.

Constante predefinite

Această extensie nu are constante definite.

Exemple

PHP/YAZ keeps track of connections with targets (Z-Associations). A resource represents a connection to a target.

The script below demonstrates the parallel searching feature of the API. When invoked with no arguments it prints a query form; else (arguments are supplied) it searches the targets as given in array host.

Example#2 Parallel searching using Yaz

<?php
$host
=$_REQUEST[host];
$query=$_REQUEST[query];
$num_hosts count($host);
if (empty(
$query) || count($host) == 0) {
    echo 
'<form method="get">
    <input type="checkbox"
    name="host[]" value="bagel.indexdata.dk/gils" />
        GILS test
    <input type="checkbox"
    name="host[]" value="localhost:9999/Default" />
        local test
    <input type="checkbox" checked="checked"
    name="host[]" value="z3950.loc.gov:7090/voyager" />
        Library of Congress
    <br />
    RPN Query:
    <input type="text" size="30" name="query" />
    <input type="submit" name="action" value="Search" />
    </form>
    '
;        
} else {
    echo 
'You searched for ' htmlspecialchars($query) . '<br />';
    for (
$i 0$i $num_hosts$i++) {
        
$id[] = yaz_connect($host[$i]);
        
yaz_syntax($id[$i], "usmarc");
        
yaz_range($id[$i], 110);
        
yaz_search($id[$i], "rpn"$query);
    }
    
yaz_wait();
    for (
$i 0$i $num_hosts$i++) {
        echo 
'<hr />' $host[$i] . ':';
        
$error yaz_error($id[$i]);
        if (!empty(
$error)) {
            echo 
"Error: $error";
        } else {
            
$hits yaz_hits($id[$i]);
            echo 
"Result Count $hits";
        }
        echo 
'<dl>';
        for (
$p 1$p <= 10$p++) {
            
$rec yaz_record($id[$i], $p"string");
            if (empty(
$rec)) continue;
            echo 
"<dt><b>$p</b></dt><dd>";
            echo 
nl2br($rec);
            echo 
"</dd>";
        }
        echo 
'</dl>';
    }
}
?>

Cuprins