Prepares for a scan

说明

void yaz_scan ( resource $id , string $type , string $startterm [, array $flags ] )

This function prepares for a Z39.50 Scan Request on the specified connection.

To actually transfer the Scan Request to the server and receive the Scan Response, yaz_wait() must be called. Upon completion of yaz_wait() call yaz_error() and yaz_scan_result() to handle the response.

参数

id

The connection resource returned by yaz_connect().

type

Currently only type rpn is supported.

startterm

Starting term point for the scan.

The form in which the starting term is specified is given by parameter type.

The syntax this parameter is similar to the RPN query as described in yaz_search(). It consists of zero or more @attr-operator specifications, then followed by exactly one token.

flags

This optional parameter specifies additional information to control the behaviour of the scan request. Three indexes are currently read from the flags array: number (number of terms requested), position (preferred position of term) and stepSize (preferred step size).

返回值

没有返回值。

范例

Example #1 PHP function that scans titles


<?php
function scan_titles($id, $startterm) 
{
  yaz_scan($id, "rpn", "@attr 1=4 " . $startterm);
  yaz_wait();
  $errno = yaz_errno($id);
  if ($errno == 0) {
    $ar = yaz_scan_result($id, $options);
    echo 'Scan ok; ';
    foreach ($options as $key => $val) {
      echo "$key = $val &nbsp;";
    }
    echo '<br /><table>';
    while (list($key, list($k, $term, $tcount)) = each($ar)) {
      if (empty($k)) continue;
      echo "<tr><td>$term</td><td>$tcount</td></tr>";
    }
    echo '</table>';
  } else {
    echo "Scan failed. Error: " . yaz_error($id) . "<br />";
  }
}
?>