You can more easily add to and edit this wiki, but if you want to add to or update the other tutorials that haven't been migrated to the wiki yet, you may follow the directions below!
Many young and very impressionable people discover SDF every day. They ask us what we might feel are stupid questions, but it's not their fault. They've grown up only knowing that hackers destroy computer networks and exploit people and their information. The solution is not to ridicule or shun these kiddiots, but to show them that there is a better and truer way. – From the README.TXT
This guide has been introduced to help members more easily contribute to the SDF Tutorials project. The first section of the guide gives brief instructions for creating or editing tutorial files using RCS for version control. The second part of the guide discusses tutorial-specific HTML coding and contains some template code.
It would behoove you to read the original
README.TXT of the SDF Tutorials Project in the tutorial files directory (
/sys/html/tutorials). It not only expresses the aim of the project, but it also contains more detailed information on the use of RCS than is given here.
This guide assumes knowledge of basic shell use and text file editing. Familiarity with HTML is not necessary, though it may prove helpful.
To create or edit a tutorial, change your working directory to
/sys/html/tutorials in your shell on the main SDF cluster (e.g. sdf.org, not MetaArray):
$ cd /sys/html/tutorials
Inside the tutorials directory, you can use
echo to quickly create an empty HTML file with an RCS Id tag at the bottom. Use the
umask command first to make sure that the permissions on the new file will allow the web server (and other users) to read it.
$ umask 022 $ echo -e "\n\$Id\$" > your_tutorial_filename.html
Use the command
ci -u to check-in the file with RCS and leave it unlocked it so that anyone can edit it.
$ ci -u your_tutorial_filename.html
The first time you check-in a file, you will be asked for a description of it. Please write something useful.
You may now edit your tutorial using the instructions in the next section to check the file in and out of RCS.
Once your tutorial is ready for public display, please add it to the list of available tutorials so people can actually find it on the web. You must edit the
index.html file in the tutorials directory to do this. When editing the
index.html file, use the same check-in/check-out procedure that you do when editing a tutorial.
Inside the tutorials directory, use the command
co -l to check out the file with RCS and lock it while you make your edits.
$ co -l filename
If when using
co -l you are told that the file is already locked please STOP what you are doing and wait for it to be checked back in. If it does not get checked back in, email the author and let them know you want to check out the file and edit it.
You may now edit the file using your preferred text editor. If you save your work periodically, you can load and reload the tutorial in your web browser to see your changes. The URL for the tutorial file will be
http://sdf.org/?tutorials/filename_without_extension (e.g., if you are editing
/sys/html/tutorials/nmap_for_dummies.html, the URL will be
When you are finished editing the file, use the command
ci -u to check the file back in with RCS and unlock it so that others may edit it.
$ ci -u filename
When you check-in a file, you will be asked to describe the changes you've made to it. Be as terse as you like, but please write something useful.
MetaARPA users can also edit the FAQs. These are plain text files, found in
/sys/html/tutorials/FAQ/. The list of FAQs for each section is in a dotfile
'.list'. These FAQ files are synced regularly with those shown by the
Tutorials are coded using HTML. If you are already handy with HTML, then you are just moments away from editing your tutorial! Please read the Before You Start Coding section for some implementation specifics, and at least skim the Coding Style section before proceeding.
If you are not familiar with HTML, the W3C site has a very brief tutorial, Getting Started With HTML, which will teach you enough of the rudiments to be able to author a tutorial. In addition, the template on this page is furnished with ample comments to help HTML beginners.
If you don't have the time or inclination to learn HTML, you may still be able to contribute to the Tutorials Project. Write a tutorial (or a section, correction, addendum, etc.) in plain text and tack a note in
bboard:<TUTORIALS>. One of your MetaARPA colleagues may just volunteer to HTMLize your work for you.
SDF tutorial files contain HTML code, but they are not complete HTML documents. When they are served to web browsers, the site's
index.cgi wraps them in the site-wide navigation header and footer. The code in tutorial files represents the contents of a
<body> element, and must not contain the following elements/tags:
Tutorial files will also contain an RCS $Id tag, which will look something like:
$Id:filename.html,v 1.11 2011/01/01 11:11:11 username Exp $. There is no need to edit this, as it is automatically generated by RCS. It is best to leave it as the last line of the file.
Do not hotlink images from other sites. Put a copy of any image files you wish to use in
/sys/html/tutorials/images, and make sure their permissions allow the web server to read them (
chmod a+r will do this).
Always provide a description of the image for users of text-based browsers and the visually impaired in the
alt attribute of the
<img src="http://sdf.org/tutorials/images/example.png" alt="Image of a Blickensderfer No. 5 typewriter>
In the event that you rely heavily upon a source in your tutorial, particularly if you use any direct quotations from it, you should cite the work properly.
Include a heading for “References”, or “Notes” in your tutorial (typically at the end) and use a numbered list (
<ol>) to enumerate your sources in the Chicago Style for Notes.
<h2 id="notes">Notes</h2> <ol> <li id="bartles">James Bartles, <cite>Boogers For Breakfast</cite> (Sacramento: Wine Cooler Press, 1979), 74.</li> <li id="moribund">Delron Moribund, "Crossover Calisthenics", <cite> Travesties of Better Judgement</cite> 64 (2009): 56-60.</li> </ol>
Then, where the sources are cited in the text of your tutorial, use a superscript (
<sup> ) number or a number in parenthesis hyperlinked to the appropriate list item.
<p>The secret to a proper nose-goblin ganache is in the picking<sup><a href="#bartles">1</a></sup>. (...)</p>
<p>Without adequate stretching beforehand, you are certain to suffer a Ludmilian haemorrhage(<a href="#moribund">2</a>). (...)</p>
There are further examples of this in the code template below.
The current W3C recommendation is HTML 5. In most respects, the core elements of HTML haven't changed since the mid 1990s; some tags have been added, and some removed. To maximize backwards compatibility, you might * restrict yourself to the following elements, which have gone unchanged since 1996:
<dl>and their subordinates
<table>and its subordinates
Many closing tags are optional, but for code clarity they can be nice. Stay away from XHTML self-closing tag forms, however (ie.
<img src=“some_url”/>, et cetera).
Furthermore, the tutorials are a collaborative effort. You may be the first author to work on a tutorial, but you probably won't be the last. If your tutorial is a hairball of style attributes and idiosyncratic tag/element usage, it only makes it harder for the next author to edit/expand – particularly if they're not as well-versed in web coding as you are.
Please try as much as possible to use plain HTML when coding tutorials. Everything you should need to write a clear tutorial is already in the language:
<h1>,<h2>;,…,<h6>), and stay away from using
<p>) for blocks of prose, and preformatted blocks (
<pre>) for source code listings, sample console output, or wherever else whitespace needs to be retained and a monospaced font used.
Rather than use styled
<span> tags or other generic grouping elements, use semantic tags which describe the text you want to differentiate from body text. If the user's browser supports the tag, it will be presented differently.
There is a usage summary of text-level semantic elements for the current W3C recommendation (HTML 5). It's handy. Not all tags are supported by all browsers, but a semantically tagged tutorial is more useful – and easier to style – than a document full of custom styled spans.
The code below may be used as a template if you are creating a new tutorial, or re-writing one from scratch. You don't have to use it; it is merely provided as a convenience.
The text contained between the
–> tokens are comments, and may be discarded.
<!-- SDF Tutorial Template ====================================================================== Use of this code is entirely optional. It is provided as a sample of coding style, and a quick way to start a new tutorial for users who may be beginners with HTML. --> <style type="text/css"> @import url('https://sdf.org/tutorials/tutorials.css'); </style> <!-- The title of the tutorial should be the only level-1 header (<h1>) in the document. --> <h1>Title of Tutorial</h1> <!-- For longer tutorials, a table of contents is nice. Shorter tutorials (like this one) really don't need it, so this section can be omitted. Replace the <ul> tags with <ol> tags for a numbered list. --> <ul> <li> <a href="#section-1">Section Heading</a> <!-- to get an indented section of the list, we simply embed a list inside of a list item --> <ul> <li> <a href="#subsection-1">Subsection Heading</a> </li> </ul> </li> <li><a href="#section-2">Another Section Heading</a></li> <li><a href="#notes">Notes</a></li> </ul> <!-- This is the beginning of a section. It starts with a level-2 heading (<h2>) and has been given an 'id' attribute so that it may be linked to. --> <h2 id="section-1">Section Heading</h2> <!-- Remember to always contain your paragraphs in <p> tags. For strings of code, filenames, commands, etc., which appear inside of a paragraph, wrap them in <code> tags to differentiate them from the rest of the paragraph's text. --> <p>By issuing the <code>sac -nar</code> command, your spirit animal will be changed to the narwhal.</p> <!-- For entire blocks of code, place the <code> inside of a <pre> instead of a <p>. Text inside of a <pre> has its whitespace characters (space, tab, carriage-return) interpreted literally, unlike text inside of a <p>. --> <pre><code>10 PRINT "DO YOU EAT BOOGERS?" 20 INPUT X 30 IF X="YES" THEN PRINT "YOU'RE A GOOD MAN, CHARLIE BROWN.": END 40 IF X="NO" THEN PRINT "WHAT, YOU THINK YOU'RE BETTER THAN ME?" </code></pre> <!-- For sample program output, console sessions, etc., use <samp> inside a <pre> block. --> <pre><samp>$ finger man@arms Login: man Name: Duncan Directory: /eternia/heroic_warriors/man Shell: /bin/bashasaurus No mail. Plan: Make Orko clean-up the mess he left in my workshop. </samp></pre> <!-- This sub-section begins with a level-3 heading (<h3>). HTML provides tags for sections nested six levels deep (tags <h1> through <h6>). If you need to nest sections seven or more levels deep ...you might consider restructuring your tutorial! --> <h3 id="subsection-1">Subsection Heading</h3> <!-- For VERY IMPORTANT TEXT, make it <strong>. To add emphasis to a word or phrase, use <em>. --> <p><strong>Do not forget to flush the buffer</strong>. If you do, the smell will be <em>intolerable</em>.</p> <h2 id="section-2">Another Section Heading</h2> <!-- This paragraph gives an example of two styles of footnote referencing. Both are hyperlinked to corresponding list items (<li>) in the Notes section below. --> <p>The Honeywell 6080 can be induced to perform a samba by pressing the button labeled "Samba" on the operator's console<a href="#fn1"><sup>1</sup></a>. That mainframe's forté, however, is the foxtrot(<a href="#fn2">2</a>), but the inducement of that particular step is beyond the scope of this tutorial.</p> <!-- Here is a sample footnotes section. In this example, we're using footnotes to cite a reference, but this same style can be used for footnotes of any kind. Your tutorial may not require any footnotes. If it doesn't, feel free to snip this entire section out. --> <h2 id="notes">Notes</h2> <!-- We're using an ordered list (<ol>) so that the notes are automatically numbered. A single reference is cited twice in the tutorial. As you can see, you may use an abbreviated form of citation for subsequent references to a single work. --> <ol> <li id="fn1">Zurgone Vemliat, <cite>Mainframe Dancing Habits</cite> (Milwaukie: Brewers' Press, 1988), 96.</li> <li id="fn2">Vemliat, <cite>Mainframe</cite>, 112.</li> </ol> <!-- At the very end, here, is the RCS Id tag. Let it be, my friend. -->
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