yaz_scan

Description

This function prepares for a Z39.50 Scan Request. Argument id specifies target ID. Starting term point for the scan is given by startterm. The form in which is the starting term is specified is given by type. Currently type rpn is supported. The optional flags specifies additional information to control the behaviour of the scan request. Three indexes are currently read from the flags: number (number of terms requested), position (preferred position of term) and stepSize (preferred step size). To actually tranfer the Scan Request to the target 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.

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

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