The database called phpbook belongs to user postgres and is located on the local host (-> Access via UNIX sockets and not TCP/IP).
pg_host causes PHP to core dump - other commands don't  seem to work properly as well.

<?php
        $connstr = "dbname=phpbook user=postgres";
        $dbh = @pg_connect($connstr);
 
        if      ($dbh)
        {
                echo "Handle exists<br>";
        }
 
        echo "Host: ".pg_host($dbh)."<br>";
        echo "Database: ".pg_dbname($dbh)."<br>";
        echo "Port: ".pg_port($dbh)."<br>";
        echo "tty: ".pg_tty($dbh)."<br>";
?>


bash-2.05$ php connect.php
X-Powered-By: PHP/4.0.6
Content-type: text/html
 
Segmentation fault