BittyWiki
Just for grins, and to flex my PHP chops, I decided to write a simple wiki system. The catch, though, is to see how short I can make the actual program; I was inspired by this Shortest Wiki Contest, though I can't profess to be quite as fanatic as those guys (I prefer readable code—squishing it all into a minimal number of obfuscated lines just seems like cheating), I think I did pretty well so far. Read through if you're interested; it's pretty technical and I include the PHP source.
The BittyWiki, as I'm calling it, is pretty limited by most wiki standards: it stores the content in flat files, doesn't do any sort of version control, or change/revision tracking, or provide a formatting scheme for text other than a subset of HTML. But it works, and I've sandboxed a bit of the functionality for basic sanity checking. And it all runs out of one file, index.php. All you'd need to do is upload that to your server, create a writeable data directory alongside it, and point your browser at it.
Links need to be structured in the form of index.php?page=pagename in the anchor tags, so the user would have to know some HTML to add pages to the system. And there's a basic safeguard against file spoofing here by taking the basename() of the page name (it's basically a user parameter, after all) and stripping all but alphanumerics and a few extra characters so we don't break the filesystem when we try to create/open the file.
Really, this is nearly as simple as I can make it, there's already even a TODO in a comment there that would add some complexity. I could shed a few more bytes by shortening up some functions (using file() instead of the fopen() stuff, reducing the number of allowable HTML tags), but that's a bit pedantic, and I rather think it's kind of elegant the way it is.
Here's the source (created using PHP's built-in highlight_file() function and copying-and-pasting). Disclaimer: If you copy this code to your server and it breaks something, don't come crying to me :).
<?php
/**
* BittyWiki
*
* How small can I make a functional wiki using PHP?
* If I attach a stylesheet, should that count against size?
*/
$page = basename($_GET['page']);
// Make sure $page is file-safe
$page = preg_replace('/[^a-zA-Z0-9._-]+/', '', $page);
$page = (!empty($page))? $page: 'index.php';
$filename = 'data/' . $page;
if ( !empty($_POST) ) {
$data = $_POST['data'];
// TODO: Only grab stuff between <body> tags
$data = strip_tags($data, '<p>,<br>,<a>,<b>,<i>,<h1>,<h2>,<h3>,<h4>,<h5>,<h6>,<ul>,<ol>,<li>,<blockquote>');
$fp = fopen($filename, 'w');
fwrite($fp, htmlspecialchars(strip_tags($_POST['title'])) . "n~n" . $data);
fclose($fp);
// Redirect to itself to avoid the refresh problem
header("Location: index.php?page=$page");
exit;
}
if ( file_exists($filename) ) {
$fp = fopen($filename, 'r');
$data = fread($fp, filesize($filename));
fclose($fp);
list($title, $data) = explode("n~n", $data, 2);
}
if ( $_GET['action'] == 'edit' ) {
?>
<html><head><title>BittyWiki: Edit <?php echo $page; ?></title></head>
<body><form method="post" action="index.php?page=<?php echo $page; ?>">
<h1>Edit <?php echo $page; ?></h1>
Title:<br />
<input type="text" name="title" size="100" value="<?php echo htmlspecialchars($title); ?>" /><br />
Body:<br />
<textarea name="data" cols="100" rows="25"><?php echo htmlspecialchars($data); ?></textarea><br />
<input type="submit" value="Save" />
</form></body></html>
<?php
} else {
?>
<html><head><title>BittyWiki: <?php echo $title; ?></title></head><body>
<?php echo $data; ?>
<hr />
<p><a href="index.php?page=<?php echo $page; ?>&action=edit">Edit this page</a></p>
</body></html>
<?php
}
?>
Comments:
Jake writes:
Man, that is pretty tidy. Now just remove all but the necessary whitespace, use shorthand versions of some of that stuff (as I think both echo and print have shorthand versions, as does some other stuff -- php guru I am not, so I may be totally wrong here), and you might be able to knock like 300 bytes off there ;-)
Oh, and use HTML 3.2 output (or just even 4) so you don't have to have extra space and the closing "/" on some tags.
Comment by Jake at 2005-06-15 15:01:07
UtterlyBoring.com writes:
Create A Wiki with Four Lines of Code?
SigWik is a Wiki that only has four lines of source code. Other programming fanatics have created 12 others that are all under 50 lines of code (in languages such...
Trackback by UtterlyBoring.com at 2005-06-15 15:21:33
Jon writes:
I was leaning towards XHTML compliance with the extra "/" for closing tags, but there's really no reason for it. echo and print don't have shorthand versions per se, but I believe you can configure PHP to mimic ASP's <%= shortcut tag for outputting, but I'd prefer to stick to pure PHP :-)
Comment by Jon at 2005-06-15 15:34:23
Jake writes:
See, that's what I used. My PHP is configured to
