dynamic on-line blog utility
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This is a read-only repository mirror for dblg, a [simple] dynamic blogging utility. dblg is a small, no-nonsense web application supporting the bare minimum required for publishing blog (or "micro-blog") content.

I run it on Mac OS X and OpenBSD (with pledge(2) support).

It has three components:

  1. A back-end server. This is a tiny CGI script written in C, dblg.c. It links to kcgi and ksql, and uses SQLite for its backing store. It produces JSON objects, an Atom feed, or static HTML5 so it can be driven by any front-end conforming to its expectations.

  2. An editing front-end, dblg.xml, dblg.css, and dblg.js. This part drives the back-end by providing an interface for saving entries, publishing them, and doing user management. The editor front-end is usually installed on the same machine as the back-end, but that's really just a matter of convenience of keeping both in sync. You can build your own editor front-end that drives the back-end server---it's just JSON and HTML forms---but that's kind of a PITA.

  3. A blog viewer front-end, blog.js and, for reference, blog.xml, blog.css. Your public-facing pages will want to be filled in with blog content, which they can do by including the JavaScript file blog.js and having an HTML element with identifier blog filled-in as in the reference. Your page will then invoke the script when desired. A static version of blog front-end, blog-static.xml, is provided (though it must be configured by the administrator) to have static blog content. The latter is required if you want your blog spidered. I use both: one for "blog" front matter and the other for permanent-link articles.

This tool is still under development, as is its documentation. For a view of it working, see my diving blog.

The project is being tracked by Coverity for static analysis of the C source code.

Some features:

  • Simple, easy-to-audit code.
  • Straightforward user administration (admins, regular users).
  • Publish directly or delay publication and edit privately.
  • Support for cloud-based images, for now limited to Cloudinary (which I use for the divelog).
  • Geolocation and coordinates attached to each entry (or suppressed).
  • Supports language tags.
  • Responsive layout for small displays.
  • Strong HTTP caching with etags, full compression support.
  • Security: cookies with security extensions and full support for CSP (no in-line JavaScript)
  • Atom feed support.
  • Static HTML support.

The default editor front-end uses moment.js for formatting dates, clipboard.js for copying to the clipboard (apparently this is hard?), and js-sha1 for SHA1 hashing the cloud authorisation.

The default viewer optionally (but strongly recommended) uses moment.js and showdown for formatting MarkDown. The default static page also uses showdown.


Beyond this document, you can also view the database schema or the RESTful API.


As mentioned, there are three components to this blogger: the back-end, the editor, and the viewer. The back-end and editor usually go in the same place, so I'll start with them.

Editor front-end and server back-end

You'll first need to download and configure the software. This is fairly straightforward. First, download. Then, open the GNUmakefile. Override the variables you'd like in a GNUmakefile.local file (which won't be touched). The GNUmakefile documents each variable and has an example deployment on a default OpenBSD machine.

You'll need kcgi and ksql for the back-end server.

Once configured, run make installcgi for first-time to install the database and the CGI script; else, make updatecgi only to freshen the CGI script and not touch the database.

If you're upgrading from an old version of dblg (i.e., with make updatecgi and differnt versions), the database may have changed. Each version with a changing upgrade has a database upgrade script as dblg-OLD-NEW.sql. Run those in order.

To install the editor tools, use make installserver. This will only install the HTML, JavaScript, and CSS for the editor.

Viewer front-end

There are two ways of "viewing" blog content. The first is to dynamically load using JSON; the second, static HTML.

Dynamic content

To install the viewer, you don't need to download this software. Simply reference the existing blog.xml and blog.css, then include blog.js files in your application.

<script src="//cdn.rawgit.com/kristapsdz/dblg/master/blog.js"></script>
  window.addEventListener('load', function(){
    blogclient('/cgi-bin/dblg', {
      blog: '/blog.html',
      editor: '/dblg.html',
      limit: 5

In this invocation, the script is pulled from GitHub's CDN and invoked in an embedded HTML script. The embedded script calls the blogclient function, passing it some example values. The blogclient function consists of two arguments:

blogclient(url, options);

The url argument is the URL of the blog CGI script. The options dictionary is optional and may consist of any or all of the following optional values:

  • blog: the URL for the blog page
  • editor: string pointing to the editor URL (no editor, if null)
  • entryid: an integer that's the unique identifier of a specific entry to pull down (if unspecified, this is checked in the query string)
  • lang: a string limiting the languages of pulled articles
  • limit: an integer limiting the number of pulled articles (else all)
  • order: a string of either ctime or mtime being the default sort order of pulled articles
  • postload: a function that is invoked after all processing has been done after successfully downloading and parsing the results
  • rescroll: a Boolean indicating that if there's a document hash, re-scroll to that hash after loading the page (and before postload)

The blogclient function asynchronously manipulates the DOM tree within and including the blog identifier, the root element that (obviously) should be included somewhere in the calling page. When blogclient is invoked, it synchronously adds the hide attribute to the root element before starting asynchronously downloading blog content.

Upon success, the child of this element is removed, cloned, and replicated for each blog element shown on the page.

<div id="blog">
    <!-- This is duplicated and filled in for each entry. -->
    <!-- Node manipulation happens over "class" attributes. -->

Within the root element, the following classes have their contents replaced by content. Note that calendar form refers to using moment.js's calendar() function, if found, or simply a generic date string otherwise. Note also that markdown refers to HTML-ised markdown if showdown is loaded, or the raw markdown otherwise.

  • blog-ctime: calendar form of entry creation time
  • blog-mtime: calendar form of entry update time, which is initialised to entry creation time
  • blog-author: name of blog entry author
  • blog-title: title of blog entry
  • blog-aside: article synopsis markdown content
  • blog-content: article content markdown content

Furthermore, the following element attributes are set or unset.

  • blog-author-link: if provided, href is set to the author's link; otherwise, the href attribute is removed
  • blog-canon-link: if a blog argument is provided to the blogclient configuration object, href is set to that and the ?entryid=nnn parameter; otherwise, the href attribute is removed
  • blog-coords: if coordinates are provided, sets href to a Google maps link (in satellite mode) of the coordinates; otherwise, the href is removed
  • blog-fb-link: if the blog argument is provided to the blogclient configuration object, data-href is set to the canonical blog link and data-numposts also set; otherwise, they are removed
  • blog-image: if provided, src is set to the image link; otherwise, the src attribute is removed
  • blog-image-link: if provided, href is set to the image link; otherwise, the href attribute is removed

The following have the hide attribute ("hidden") set on the containing element given the noted conditions.

  • blog-canon-box: hidden if a blog argument is not provided to the blogclient configuration object
  • blog-coords-box: hidden if there are no coordinates
  • blog-ctime-box: hidden if there is a modification time
  • blog-image-box: hidden if there is no image
  • blog-mtime-box: hidden if there is not a modification time

After filling in these fields for each blog entry, the hide class is removed from the root element.

Static content

Static content is full-formed HTML5 produced by the back-end. To use this mode, which is not enabled by default, you'll need to enter the administration page and provide a template that will be filled in by the back-end and passed to the front-end. A sample is provided in blog-static.xml. This is not installed by default: you'll need to copy it into your web root and point to it in the administrative console.

The following template keys are populated:

  • dblg-aside: aside content (Markdown)
  • dblg-author-link: link to author, if given (otherwise blank)
  • dblg-author-name: author name
  • dblg-canon: canonical link to blog entry
  • dblg-canon-query: blog entry query string
  • dblg-classes: a string consisting of zero or more author-has-link, blog-has-aside, blog-has-image, blog-has-image-aside, blog-has-only-aside, blog-has-only-image, blog-has-only-ctime, blog-has-mtime, blog-has-coords (explanation fairly self explanatory)
  • dblg-content: content (Markdown)
  • dblg-coord-lat-decimal: latitude decimal (if coordinates given, else empty)
  • dblg-coord-lng-decimal: longitude decimal (if coordinates given, else empty)
  • dblg-ctime: epoch date of creation time
  • dblg-ctime-iso8601: ISO 8601 formatted creation time
  • dblg-image: blog image (if given)
  • dblg-mtime: epoch date modification time (starting with creation time)
  • dblg-mtime-iso8601: ISO 8601 formatted modification time
  • dblg-title: entry title (not Markdown)


All sources use the ISC (like OpenBSD) license. See the LICENSE.md file for details.