, October 2002.
$Id: imagesrv.hack,v 1.6 2002/12/18 10:57:54 cky Exp $
Copyright (c) 2002 Chris K. Young. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public Licence as published by
the Free Software Foundation; either version 2 of the Licence, or (at
your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public Licence for more details.
You should have received a copy of the GNU General Public Licence
along with this program; if not, write to Free Software Foundation,
Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
*/
/*
This program reads a CDB database named imagesrv.cdb, which can
contain multiple collections of files. For each collection, named
$FILE in this description, a number of keys should exist:
0$FILE
Contains as its value a decimal representation of the number
of files in the collection.
1$FILE
Contains the first file in the collection, represented as the
MIME type of the file, a null character, and then the contents
of the file itself.
10$FILE
Contains the tenth file in the collection, if there are that
many.
*/
class imagesrv {
/* Once and only once. */
function open_cdb() {
return dba_open('imagesrv.cdb', 'r', 'cdb');
}
function print_header() {}
function validate_input() {
return isset($_GET['file']);
}
function process_input() {
if (!($cdb = $this->open_cdb()))
return;
$file = $_GET['file'];
if (!($items = dba_fetch("0$file", $cdb))) {
header('Content-Type: text/plain');
print("Whoa! The file collection $file does not exist.\n");
dba_close($cdb);
return;
}
list($l, $r) = array($_GET['l'], $_GET['r']);
if (!isset($l) || $l < 1)
$l = 1;
if (!isset($r) || $r > $items)
$r = $items;
if ($l > $r) {
header('Content-Type: text/plain');
printf("Oops! l (%u) seems to be greater than r (%u).\n", $l, $r);
dba_close($cdb);
return;
}
$pos = mt_rand($l, $r);
$data = dba_fetch("$pos$file", $cdb);
dba_close($cdb);
if (!$data) {
header('Content-Type: text/plain');
print("Oops! It seems we have an internal error here (key).\n");
return;
}
if (!($pos = strpos($data, "\0"))) {
header('Content-Type: text/plain');
print("Oops! It seems we have an internal error here (value).\n");
return;
}
header(sprintf('Content-Type: %s', substr($data, 0, $pos)));
if (($refresh = $_GET['refresh']) > 0)
header(sprintf('Refresh: %u', $refresh));
print(substr($data, $pos + 1));
}
function print_form() {
$tmpl = new template('The imagesrv gimmick');
$tmpl->set_rcsid('$Id: imagesrv.hack,v 1.6 2002/12/18 10:57:54 cky Exp $');
$tmpl->print_header();
$files = array();
if ($cdb = $this->open_cdb()) {
for ($key = dba_firstkey($cdb); $key; $key = dba_nextkey($cdb))
if ($key[0] == '0')
$files[] = substr($key, 1);
dba_close($cdb);
}
?>
The imagesrv gimmick was originally written to allow serving a random image from a collection of images. However, it is general enough to be able to serve files of any type.
Currently, the following collections are available:
%s\n", $self,
urlencode($val), htmlspecialchars($val));
?>
Sorry, there are currently no collections available. Please check again another day!
print_footer();
}
function print_footer() {}
}
?>