Úvod
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 SQL APIs that are available
for PHP. This means that sessions are stateless but shared amongst
users, thus saving the connect and initialize phase steps in most
cases.
YAZ is available at http://www.indexdata.dk/yaz/. You can find news information,
example scripts, etc. for this extension at http://www.indexdata.dk/phpyaz/.
Instalace
Compile YAZ and install it. Build PHP with your favourite
modules and add option
--with-yaz.
Your task is roughly the following:
Konfigurace běhu
Chování těchto funkcí je ovlivněno nastavením parametrů v php.ini.
Tabulka 1. YAZ configuration options
| Name | Default | Changeable |
|---|
| yaz.max_links | "100" | PHP_INI_ALL |
| yaz.log_file | "" | PHP_INI_ALL |
For further details and definition of the PHP_INI_* constants see
ini_set().
Typy prostředků
Toto rozšíření nemá definován žádný typ prostředku
(resource).
Předdefinované konstanty
Toto rozšíření nemá definovány žádné
konstanty.
Příklady
PHP/YAZ keeps track of connections with targets
(Z-Associations). A positive integer represents the ID of a
particular association.
Příklad 1. Parallel searching using YAZ()
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 in array
host.
$num_hosts = count ($host);
if (empty($term) || count($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="1"
name="host[]" value="z3950.bell-labs.com/books">
BELL Labs Library
<br>
RPN Query:
<input type="text" size="30" name="term">
<input type="submit" name="action" value="Search">
';
} else {
echo 'You searced for ' . htmlspecialchars($term) . '<br>';
for ($i = 0; $i < $num_hosts; $i++) {
$id[] = yaz_connect($host[$i]);
yaz_syntax($id[$i],"sutrs");
yaz_search($id[$i],"rpn",$term);
}
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 ereg_replace("\n", "<br>\n",$rec);
echo "</dd>";
}
echo '</dl>';
}
} |
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