The Simple Nice-Looking Manual Generator
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The Simple Nice-Looking Manual Generator

Copyright John Morrice 2010


This document is released under the terms of the GNU Free Documentation License. See the file  DOC-COPYING (see  DOC-COPYING) for details

All snm source code is released under the terms of the GNU General Public Licence Version 3.  See the file  COPYING (see  COPYING) for details.

The Simple Nice-Looking Manual Generator - A.K.A snm - generates nice looking manuals from  YAML (see files.

Currently, it can produce XHTML and text manuals.

snm is  hosted on github (see


1. What snm does and is
2. What snm does not do and is not
3. Building snm
   3.1. The Easy Way
   3.2. The Hard Way
   3.3. Install snm to /usr/bin
4. Invoking snm
5. How to use snm
   5.1. header.yaml
   5.2. Sections
      5.2.1. Subsections
   5.3. Paragraphs
   5.4. Banners
   5.5. Inline Elements
      5.5.1. Hyperlinks
      5.5.2. Literal text
      5.5.3. Inline classes
   5.6. Style: CSS
6. Further help, misuse and shortfalls

1. What snm does and is

snm allows you to write clean, web-friendly reports, user guides and manuals without having to edit fickle html.

snm allows you to structure your document in a modular fashion.

snm document sections are written in yaml and are easy to write and understand.

snm is a generator of small, valid xhtml files.

2. What snm does not do and is not

snm is not (currently) a man-page generator.

snm is not a web-page creator

snm is not a gui based tool

snm is not an adult activity.

3. Building snm

First, install  libsyck (see

Then choose to proceed to build snm in either  The Easy Way or  The Hard Way.

The hard way is presented to give more information to people who may need it.  The Easy Way is recommended for absolutely everyone else!

3.1. The Easy Way

First install  The Haskell Platform (see

Then just do:

cabal install snm

Now  install snm to /usr/bin

3.2. The Hard Way

To build snm the hard way, you must install:

 The Glasgow Haskell Compiler (see  snm has been tested with GHC 6.10.4

And from  Hackage (see, the following libraries

base>=4, parsec>=3, filepath, directory, containers, HsSyck, safe, SpoonsUtilities, xhtml

Download the source distribution of snm from github

cd into its directory.


   cabal install

Now  install snm to /usr/bin

3.3. Install snm to /usr/bin

cabal install typically installs snm into your local cabal directory, usually ~/.cabal/bin/snm

So you'll probably need to:

   sudo cp ~/.cabal/bin/snm /usr/bin

Now, try to  invoke snm

4. Invoking snm

Once it is  installed, try invoking snm with

   snm --help

If it was successfully installed, you will see some helpful information and a list of snm's command line options:

   snm: The Simple Nice-Looking Manual Generator 
      snm documentation_source_directory options* 
   Where options* stands for zero or more of the options below. 
      Only one output format is permitted per invocation. 
      If -d or --dump is used, snm will not write a file unless -o or  
      --output is  used. 
      There can be no whitespace between -o and its argument, nor can 
      there be whitespace between --output= and its argument. 
      If no arguments are given to -o, then the file written will have  
      the same filename as the documentation source directory, with an  
      appropriate extension added. 
      snm will always add an appropriate extension to output files. 
      By default, snm will produce xhtml, and act as if the user had  
      specified -o without an argument. 
      -d               --dump                  Print output to stdout. 
      -o[A file name]  --output[=A file name]  Write output to a file.   
                                               Multiple outputs ignored,  
                                               printing warning to  
      -h               --help                  Print usage information 
      -t               --text, --txt           Text output. 
      -x               --xhtml, --html         Output in xhtml format.

5. How to use snm

snm generates a manual from a number of yaml files, held in a documentation source directory.  In the snm source distribution, this directory is called 'snm_help'.

This source directory must contain a file called 'header.yaml'.  The next sub-section deals with what you put in header.yaml, and what it means.

5.1. header.yaml

The header file has 1 required field:

   title: A  banner, the title of the manual.

The header file has 2 optional fields:

   banners: Zero or more  banners, used to announce important things at the start of a manual, for example, its author.  
   preamble: Zero or more  paragraphs, which are not included in the manual's  contents.

For example, here is a slightly simplified version of the header.yaml file for this document:

   title: "The Simple Nice-Looking Manual Generator" 
      - "Copyright John Morrice 2010" 
      - "Contact" 
      - "This document is released under the terms of the GNU Free Documentation License. See the file  DOC-COPYING (see  DOC-COPYING) for details" 
      - "All snm source code is released under the terms of the GNU General Public Licence Version 3.  See the file  COPYING (see  COPYING) for details." 
      - "The Simple Nice-Looking Manual Generator - A.K.A snm - generates nice looking manuals from  YAML (see files." 
      - "Currently, it can produce XHTML and text manuals."

You can see how snm processes this by looking at the  top (see  #) of the document.

When emitting xhtml, the notices displayed at the top of the page are automatically given the css class 'banner'.

5.2. Sections

An snm manual, much like other structured documents, is arranged into heirarchical sections and  subsections.

Top level sections are described by yaml files in the documentation source directory.

A section file in the top directory can be given any filename, other than  header.yaml and  style.css which are reserved.  This restriction does not apply to subsections.

Each section has 4 required fields:

   title: A  banner, the title of the section.  This section's title is 'Sections' 
   number: the number of the section.  This section's number is 2. 
   unique: A one-word, unique identifier for this section.  This is used in constructing  hyperlinks. 
   text: Zero or more  paragraphs.

For a concrete example, here is the beginning of the section file for this section.

   title: Sections 
   number: 2 
   unique: sections 
      - 'An snm manual, much like other structured documents, is arranged into heirarchical sections...

5.2.1. Subsections

A section is associated with subsections when the subsection files are located in a directory which has the same filename (excluding extensions) as its section file, in its same directory.

For example, here is a partial listing of this manual's source directory, snm_help:

      ...more files

Note the file 'how.yaml'.  This is the file describing  section 3, How to use snm, of this document.

Note also the directory called how.  This directory contains the subsections associated with how.yaml. Inside the how directory:

      ...more files

Note the 'section.yaml' file, which describes  section 3.2, Sections and its associated subsection directory 'section'.

Inside the section directory:


how/section/subsection.yaml is the file describing this section.

A subsection's number is automatically computed by snm.  Hence, according to the file describing this section, this section's number is 1.  snm has discovered it is nested within section 3.2.  It is an error to specify a subsection's whole number within a section file.  Specify one number only!

5.3. Paragraphs

When a sequence of paragraphs is called for in a manual yaml file, either a single text element, or a yaml  sequence (see is expected.

Paragraphs are not just plain text:  they may contain  inline elements like hyperlinks or literal text.

In a produced manual, a series of paragraphs are rendered with two line breaks between each of them.  This corresponds to two newline characters in a text document, and being within a <p> tag in an html document.  An example:

   This is a valid, although boring, paragraph.

Paragraphs can be associated with a class, using a yaml  map (see  When rendering xhtml documents, this class is becomes the value of the class attribute for the paragraph produced.  This is useful when working using a  style sheet.  An example:

   class: curved_corner 
   text: This paragraph is a bit more exciting, because it is being given curved corners by css!

Word wrapping can be turned on or off on a paragraph basis, by setting wrap to True or false in a map paragraph.  When emitting xhtml, if wrap is off, then all spaces are replaced by &nbsp; and all new-lines replaced by <br/>.  By default wrapping is on. Example:

This paragraph...

   wrap: False 
   text: "Hey ho, 
          \n  let's go!"

Is rendered as:

   "Hey ho, 
        let's go!"

But this paragraph...

   wrap: True 
   text: "Hey ho, 
          \n  let's go!"

And this paragraph...

   "Hey ho, 
    \n  let's go!"

Are rendered as:

   Hey ho, let's go!

5.4. Banners

Banners appear at the top of the manual, and at the beginning of sections.

Banners may contain inline elements in the same manner as a paragraph.

Banner defined in the  header file are, by default, given the class 'intro_banner'.  Banners defined in  sections are given the class 'banner'.

The default banner classes can be replaced by user defined classes, in the same manner that a class can be assigned to a paragraph.

5.5. Inline Elements

Inline elements within paragraphs and banners allow more expressive text.  The idea of an inline snm element is roughly equivalent to an inline HTML element.  Much as an xhtml anchor can only appear within an xhtml block element, an inline element can only appear within an snm paragraph or banner.

Inline elements appear within curly braces { }.

If you need to actually write an opening brace in your document, the opening brace may be escaped with a backslash \.

The following inline elements are available: section links, external links, inline classes and literal text.

5.5.1. Hyperlinks

snm supports two types of links.

Section links are hyperlinks to a  section of the document, using that section's unique name.

External links are a more traditional link to a URL.

As an inline element, links begin with an opening curly brace {.

Then either the word 'section', which indicates a section link, or the word 'external' which indicates an external link.

Then the link text.  This may consist of a number of words separated by whitespace.

Then the destination.  No explicit syntax separates the link text from the destination - the last word is taken to be the destination.  Obviously, section links expect a section's unique name, whereas external links expect a URL.

As with all inline elements, a link is closed with a curly brace }.

Whitespace is optional throughout links.


The link above, which is a section link to the unique identifier 'sections':

   {section section of the document sections}

The external link in  section 3.3 Paragraphs, to the 'YAML in Five Minutes' tutorial

   {external sequence}

5.5.2. Literal text

Literal text can be specified through the literal inline element.

Literal text is not processed or transformed by snm:  it is output directly into the output document.

This is risky because allows it you to write invalid xhtml, for instance; but it does allow you to write html that snm does not generate.

However, this approach suffers from many problems and is very much a working solution for current needs.  Problems are discussed  below.


   {literal <table><td>Embed a html table</td></table>}

5.5.3. Inline classes

snm supports inline classes.  This allows a section of text to have a different style to the rest of the text block.

An inline class in an inline element beginning with the word class, and lasting until the closing brace.

An example:

   class: quote 
   text: "Don't make me angry. You wouldn't like me when I'm angry" {class -- David Banner, The Incredible Hulk, 1978. aside}

The text within the class element is assigned the class 'aside', allowing it to be rendered differently from the rest of the paragraph.

In the xhtml renderer, an inline class element:

   {class the text goes here x}

Corresponds to a span element thus:

   <span class="x">the text goes here</span> 

5.6. Style: CSS

When generating xhtml, snm will look for a file called 'style.css' in the documentation source directory, and embed the contents of that file into the document's header as a CSS style sheet.

6. Further help, misuse and shortfalls

If you use snm and need more help than is available in this manual then do not hesitate to contact the author at

Please note that snm suffers from a number of shortfalls:

Invalid xhtml can be generated through manipulation of the  style sheet,  literal text,  link destinations, and the  unique names of sections.

While I regret that this is possible, attempting xhtml kludges through these means ill-fitting means is misuse of snm and may result in generation shoddy manuals, a telling off and early bed-times all around.  You have been warned!