python txt2tags-tml -t tml --toc userguide.t2t

Txt2tags User Guide

**
Aurelio, Sat Apr 28 17:55:23 2012




Part I - Introducing Txt2tags

The First Questions You May Have

This chapter is a txt2tags overview, that will introduce the program purpose and features.


What is it?

Txt2tags is a text formatting and conversion tool.

Txt2tags converts a plain text file with little marks, to any of the supported targets:


Why should I use it?

You'll find txt2tags really useful if you:

  • Need to publish documents in different formats
  • Need to maintain updated documents in different formats
  • Write technical documents or guides
  • Don't know how to write a document in a specific format
  • Don't have an editor for a specific format
  • Want to use a simple text editor to update your documents

And the main motivation is:

  • Save time, writing contents and forgetting about formatting


Why is it a good choice among other tools?

Txt2tags has a very straight way of growing, following basic concepts. These are the highlights:

Source File Readable Txt2tags marks are very simple, almost natural.
Target Document Readable The target document is also readable, with indentation and spacing.
Consistent Marks Txt2tags marks are simple symbols, designed to be unique enough to don't mix up with the document contents.
Consistent Rules As the marks, the rules that applies to them are tied to each other, there are no "exceptions" or "special cases".
Simple Structures All the supported formatting are simple, with no extra-options or complicated behavior modifiers. A mark is just a mark, with no options at all.
Easy to Learn With simple marks and readable source, the txt2tags learning curve is user friendly.
Nice Examples The sample files included on the package gives real life examples of documents written for txt2tags.
Valuable Tools The syntax files included on the package help you to write documents with no syntax errors.
Three User Interfaces There is a user friendly Graphical interface, a handy Web interface easy to install in intranets and a Command Line interface for power-users and scripting.
Scripting With the full featured command line mode, an experienced user can automatize tasks and do post-editing on the converted files.
Download and Run / Multi-platform Txt2tags is a single Python script. There is no need to compile it or download extra modules. So it runs nicely on *NIX, Linux, Windows and Macs.
Mature First released in 2001, txt2tags is now a mature program with years of improvements and bug fixes, extensive documentation, translations and an loyal user base.


Do I have to pay for it?

Absolutely NO!

It's free, GPL licensed.


Supported Formatting Structures

The following is a list of all the structures supported by txt2tags.

  • header (document title, author name, date)
  • section title (numbered or not)
  • paragraphs
  • font beautifiers
    • bold
    • italic
    • underline
    • strike
  • monospaced font (verbatim)
    • monospaced inside paragraph
    • monospaced line
    • monospaced area (multiline)
  • quoted area
  • link
    • URL/Internet links
    • e-mail links
    • local links
    • named links
  • lists
    • bulleted list
    • numbered list
    • definition list
  • horizontal separator line
  • image (with smart alignment)
  • table (with or without border, smart alignment, column span)
  • macros (with flexible formatting):
    • current date
    • file modification time
    • input and output file name and path
    • automatic table of contents
  • special mark for raw text (no marks parsed inside)
  • special mark for tagged text (no parsing, sent directly to output)
  • comments (for self notes, TODO, FIXME)


Supported Targets

HTML
Everybody knows what HTML is. (hint: Internet)

Txt2tags generates clean HTML documents, that look pretty and have its source readable. It DOES NOT use javascript, frames or other futile formatting techniques, that aren't required for simple, techie documents. But a separate CSS file can be used if wanted. Txt2tags generates "_HTML 4.0 Transitional_" code.

Txt2tags HTML generated code is 100% approved by the w3c validator.

XHTML
It is the new generation of HTML, with more strict rules. This makes the code easier to parse and understand. For the general purpose, consider it HTML. Txt2tags generates "_XHTML 1.0 Transitional_" code.

Txt2tags XHTML generated code is 100% approved by the w3c validator.

SGML
It is a common document format which has powerful conversion applications (linuxdoc-tools). From a single SGML file you can generate HTML, PDF, Post Script, Info, La Te X, Ly X, RTF and XML documents. The tools also does automatic TOC and break sections into subpages.

Txt2tags generates SGML files in the Linux Doc system type, ready to be converted with linuxdoc-tools without any extra catalog files or any SGML annoying requirements.

LATEX
The preferred academic document format, it is more powerful than you ever wondered. Full books, complicated formulas and any complex text can be written in La Te X. But prepare to loose your hair when you try to write the tags by hand...

Txt2tags generates ready-to-use La Te X files, doing all the complex escaping tricks and exceptions. The writer just need to worry about the text.

LOUT
Very similar to La Te X in power, but with an easier syntax using "@" instead "\" and avoiding the need of braces in common situations. Its approach of everything-is-an-object makes the tagging much saner.

Txt2tags generates ready-to-use Lout files, which can be converted do PS or PDF files using the "lout" command.

MAN
UNIX man pages resist over the years. Document formats come and go, and there they are, unbeatable.

There are other tools to generate man documents, but txt2tags has one advantage: one source, multi targets. So the same man page contents can be converted to an HTML page, Wiki document and plain text.

MGP
MagicPoint is a very handy presentation tool (hint: Microsoft Power Point), that uses a tagged language to define all the screens. So you can do complex presentations in vi/emacs/notepad.

Txt2tags generates a ready-to-use .mgp file, defining all the necessary headers for fonts and appearance definitions, as long as international characters support.

Txt2tags creates "diet" .mgp files: they use the Type1 fonts, so you do not need to carry True Type fonts files with your presentation. Also, the color definitions are simple, so even on a poor color palette system (such as startx -- -bpp 8), the presentation will look pretty!

The key is: convert and use. No quick fixes or requirements needed.

WIKI
You've heard about the Wikipedia, right? So you don't need to learn yet-another markup syntax. Just stick with txt2tags and let it convert your text to the Wikipedia format, called MediaWiki.

GWIKI
Now you can easily paste your project's current documentation into the Google Code Wiki.

DOKU
DokuWiki is a standards compliant, simple to use Wiki, mainly aimed at creating documentation of any kind. It is targeted at developer teams, workgroups and small companies. It has a simple but powerful syntax which makes sure the data files remain readable outside the Wiki and eases the creation of structured texts. All data is stored in plain text files - no database is required.

MOIN
You don't know what MoinMoin is? It is a WikiWiki!

Moin syntax is kinda boring when you need to keep {{{'''''adding braces and quotes'''''}}}, so txt2tags comes with the simplified marks and unified solution: one source, multi targets.

PM6
Adobe Page Maker 6.0 has its own tagged language. Styles, color table, beautifiers, and most of all the Page Maker mouse-clicking features are also available on its tagged language. You just need to access the "Import tagged text" menu item. Just for the records, it's an <HTML "like"> tag format.

Txt2tags generates all the tags and already defines a extensive and working header, setting paragraph styles and formatting. This is the hard part.

Author's note: My entire portuguese regular expression's book was written in VI, then converted to Page Maker with txt2tags and went to the publisher. It works smile

TXT
TXT is text. Simple, pure, beautiful.

Although txt2tags marks are very intuitive and discrete, you can remove them by converting the file to pure TXT.

The titles are underlined, and the text is basically left as is on the source.

Tip: Use the --targets command line option to get a complete list of all the available targets.


Status of Supported Structures by Target

Structure html xhtml sgml dbk tex lout man mgp creole wiki gwiki pmw doku moin pm6 adoc art txt
headers Y Y Y Y Y Y Y Y - - - Y - - N - Y Y
section title Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y
paragraphs Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y
bold Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y - -
italic Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y - -
underline Y Y - Y Y Y - Y - Y - Y Y Y Y N - -
strike Y Y N N Y - - - - Y Y Y Y Y N N - -
monospaced font Y Y Y Y Y Y - Y - Y Y Y Y Y Y Y - -
verbatim line Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y - -
verbatim area Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y - -
quoted area Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y N Y Y
internet links Y Y Y Y - - - - Y Y Y Y Y Y - Y - -
e-mail links Y Y Y Y - - - - Y Y Y Y Y Y - Y - -
local links Y Y Y Y N N - - N N N Y Y Y - N - -
named links Y Y Y Y - - - - Y Y Y Y Y Y - Y - -
bulleted list Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y
numbered list Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y
definition list Y Y Y Y Y Y Y N Y Y - Y - Y N N Y Y
horizontal line Y Y - N Y Y - Y Y Y - Y Y Y N N Y Y
image Y Y Y Y Y Y - Y Y Y Y Y Y Y N Y - -
table Y Y Y N Y N Y N Y Y Y Y Y Y N N N N
Extras html xhtml sgml dbk tex lout man mgp creole wiki gwiki pmw doku moin pm6 adoc art txt
image align Y Y N N N Y - Y N Y - N Y N N N - -
table cell align Y Y Y N Y N Y N N N - N - Y N N N N
table column span Y Y N N Y N N N N N - N - N N N N N

Legend
Y Supported
N Not supported (may be in future releases)
- Not supported (can't be done on this target)


The Three User Interfaces: Gui, Web and Command Line

As different users have different needs and environments, txt2tags is very flexible on how it runs.

There are three User Interfaces for the program, each one with its own purpose and features.

  • Gui: Written in Tk, brings the windowing and clicking to txt2tags.
  • Web: Written in PHP, allows users to run txt2tags on the browser,
requiring no installation on the client side.
  • Command Line: Written in Python, it's the program core. All
features are available as command line options.


Graphical Interface

Since version 1.0, there is a nice Graphical Interface, that works on Linux, Windows, Mac and others. Just call txt2tags with the --gui option to open it.

The interface is pretty simple and intuitive:

  1. You locate the source .t2t file on the disk and its options are
loaded.
  1. If the target is still empty, you must choose one.
  2. Then there are some options you may choose, but none of them are
required.
  1. Finally, press the "Convert!" button.

A nice option is the "_Dump to screen_", so you can check the resulting code on a separate window, no file is saved at all. When the code is OK, you uncheck it and the file will be saved.

The default interface colors can be changed on the configuration file, using the %!guicolors settings. For example:

% set my own colors for the graphical interface (bg1, fg1, bg2, fg2)
%!guicolors: blue white brown yellow


Web Interface

The Web Interface is up and running on the Internet at http://txt2tags.org/online.php, so you can use and test the program instantly, before download.

One can also put this interface on the local intranet avoiding to install txt2tags in all machines.


Command Line Interface

For command line power users, the --help should be enough:

Usage: txt2tags [OPTIONS] [infile.t2t ...]

      --targets       print a list of all the available targets and exit
  -t, --target=TYPE   set target document type. currently supported:
                      adoc, art, creole, dbk, doku, gwiki, html, lout, man,
                      mgp, moin, pm6, pmw, sgml, tex, txt, wiki, xhtml
  -i, --infile=FILE   set FILE as the input file name ('-' for STDIN)
  -o, --outfile=FILE  set FILE as the output file name ('-' for STDOUT)
      --encoding=ENC  set target file encoding (utf-8, iso-8859-1, etc)
      --toc           add an automatic Table of Contents to the output
      --toc-level=N   set maximum TOC level (depth) to N
      --toc-only      print the Table of Contents and exit
  -n, --enum-title    enumerate all titles as 1, 1.1, 1.1.1, etc
      --style=FILE    use FILE as the document style (like HTML CSS)
      --css-sugar     insert CSS-friendly tags for HTML/XHTML
      --css-inside    insert CSS file contents inside HTML/XHTML headers
  -H, --no-headers    suppress header and footer from the output
      --mask-email    hide email from spam robots. x@y.z turns &lt;x (a) y z&gt;
      --slides        format output as presentation slides (used by -t art)
      --width=N       set the output's width to N columns (used by -t art)
      --height=N      set the output's height to N rows (used by -t art)
  -C, --config-file=F read configuration from file F
      --gui           invoke Graphical Tk Interface
  -q, --quiet         quiet mode, suppress all output (except errors)
  -v, --verbose       print informative messages during conversion
  -h, --help          print this help information and exit
  -V, --version       print program version and exit
      --dump-config   print all the configuration found and exit
      --dump-source   print the document source, with includes expanded

Turn OFF options:
     --no-css-inside, --no-css-sugar, --no-dump-config, --no-dump-source,
     --no-encoding, --no-enum-title, --no-headers, --no-infile,
     --no-mask-email, --no-outfile, --no-quiet, --no-rc, --no-slides,
     --no-style, --no-targets, --no-toc, --no-toc-only

Example:
     txt2tags -t html --toc file.t2t

By default, converted output is saved to 'infile.&lt;target&gt;'.
Use --outfile to force an output file name.
If  input file is '-', reads from STDIN.
If output file is '-', dumps output to STDOUT.

Please read the txt2tags man page for detailed information about options and command line use.

Examples:

Convert to HTML $ txt2tags -t html file.t2t
The same, using redirection $ txt2tags -t html -o - file.t2t > file.html
  .
Including Table Of Contents $ txt2tags -t html --toc file.t2t
And also, numbering titles $ txt2tags -t html --toc --enum-title file.t2t
  .
Contents quick view $ txt2tags --toc-only file.t2t
Maybe enumerate them? $ txt2tags --toc-only --enum-title file.t2t
  .
One liners from STDIN =$ echo -e "\n**bold**" txt2tags -t html --no-headers -=
Testing Mask Email feature =$ echo -e "\njohn.wayne@farwest.com" txt2tags -t txt --mask-email --no-headers -=


Part II - Install

Just download the program and run it on your machine.

Download & Install Python

First of all, you must download and install Python on your system. Txt2tags requires Python version 2.2 or newer.

Note that Python is already installed by default in Linux and Mac systems. If you're using those, you're done, just skip this step.

If you are not sure if you have Python or not, open a console (tty, xterm, MSDOS, Terminal.app) and type python. If it is not installed, the system will tell you.

Download txt2tags

The official location for txt2tags distribution is on the program site, at http://txt2tags.org. Just download and uncompress the package (.tgz file).

If you're in Linux, you can also use the automatic installer of your system. Some examples:

  • yum install txt2tags
  • sudo apt-get install txt2tags

Install txt2tags

As a single Python script, txt2tags needs no installation at all.

The only file needed to use the program is the txt2tags script. The other files of the package are documentation, tools and sample files.

The fail-proof way to run txt2tags, is calling Python with it:

prompt$ python txt2tags

If you want to install txt2tags on the system as a stand alone program, just copy the txt2tags script to a system PATH directory and make sure the system knows how to run it.

UNIX/Linux/Mac
Make the script executable (chmod +x txt2tags) and copy it to a $PATH directory (cp txt2tags /usr/local/bin)

Windows
Rename the script adding the .py extension and copy it to a system PATH directory, such as C:\Windows\System32.

After that, you can create an icon on your desktop for it, if you want to use the program's Graphical Interface.

Install Text Editor Syntax Highlighting File (optional)

Txt2tags comes with handy syntax highlighting files to be used by the following text editors:

  • Vim
  • Emacs
  • Nano
  • Kate
  • Gedit
  • JOE
  • le
  • ne
  • Text Mate

This syntax highlighting files have all the txt2tags rules and marks registered, helping the user to write error-free documents. Showing the marks in colors, you see on-the-fly if you wrote it right.

Sample file opened in Vim Editor

Each editor has a different install procedure for a syntax highlighting file, please read the syntax file headers and the editor documentation.


Part III - Writing and Converting Your First Document

Check the Tools

To make the first conversion you will need three things: txt2tags, a text editor and a web browser.

  1. Make sure txt2tags is installed and running on your system.

    • Command Line Interface: Call "txt2tags" on the command line and
the program should give you a "Missing input file" message. If it is not working, try python /path/to/txt2tags or even /path/to/python /path/to/txt2tags if Python is not on your PATH.

    • Gui Interface: Click on the program icon to launch the Gui
Interface or call txt2tags --gui.

  1. Open the text editor your are comfortable with. It can be any text
editor, from the good old VI to MS Word or Open Office.org. Create a brand new empty document to be your first txt2tags one and remember to save it as plain text.

  1. Launch your favorite web browser to see the results of the conversion.


Write the Document Header

  1. Go to the text editor and on the very first line type the document
main title: My First Document
  1. On the second line make a subtitle, inserting this text:
A txt2tags test
  1. Then, on the third line, put some time information:
Sunday, 2004

If everything went right, you should be seeing a three line document with this contents:

My First Document
A txt2tags test
Sunday, 2004

This is just a part of the document, but we can already convert it and check the results.

Now save this document with the name test.txt. Remember to save it as plain text. Pay attention to which folder you are saving the file, you will need to remember it soon.


The First Conversion - Gui Interface

If you are in the Command Line Interface, please skip this step and read the next one.

If you are in the Gui Interface, follow this steps:

  1. Press the "Browse" button and choose the test.txt you just saved
(remember the folder!).
  1. Back to the first screen, select "HTML page" on the "Target document
type" combo.
  1. Press the "Convert!" button.

A dialog box will appear, telling you that the file was converted successfully. Note that the generated HTML page was saved on the same folder as the text file, with the "html" extension.


The First Conversion - Command Line Interface

If you are in the Command Line Interface, move to the folder where the file was saved and type this command:

txt2tags --target html test.txt

The option --target is followed by the "html" string, which tells the program to what format your text file will be converted. The last item is the text filename.

The results were saved to the test.html file and then the program will show you the "_txt2tags wrote test.html_" message. If some error occurred, read the message carefully.

Here is a sample of how it will be shown on your screen:

prompt$ txt2tags --target html test.txt
txt2tags wrote test.html
prompt$


Check the Results

Open the test.html file on the web browser to check if everything is ok.

Here it is! You just typed three simple lines of text and txt2tags made all the work to set the HTML page heading information, text alignment, sizes, spacing and appearance. See that the main title is also placed at the browser title bar.

You write text, txt2tags does the rest wink

Tip: You can also use CSS files on HTML pages generated by txt2tags, so the page appearance is 100% configurable.


Writing the Document Body

Now back to the text editor, the next step is to type the document contents. You can write plain text as you normally do on email messages. You will see that txt2tags recognizes paragraphs and list of items automatically, you don't have to "mark" them.

Then again: save it, convert and check the results. This is the development cycle of a document in txt2tags. You just focus on the document contents, finishing documents faster than other editors. No mouse clicking, no menus, no windows, no distraction.

Considering the following contents for the test.txt file, which is only plain text, compare the generated HTML page:

My First Document
A txt2tags test
Sunday, 2004

Well, let's try this txt2tags thing.
I don't know what to write.

Mmmmmm, I know what I need to do now:
- Take a shower
- Eat a pizza
- Sleep

You can write a full homepage with 0% of HTML knowledge. You don't need to insert any tags. And more, the same text file can be converted to any of the other txt2tags supported formats.

Besides plain text, txt2tags has some very simple marks, that you'll use when you need some other formatting or structures like bold, italic, title, images, table and other. As a quick sample, **stars for bold** and = equals for title =. You can learn the marks on the Txt2tags Markup Demo.


Part IV - Mastering Txt2tags Concepts

The .t2t document Areas

Txt2tags marked files are divided in 3 areas. Each area has its own rules and purpose. They are:

Header Area
Place for Document Title, Author, Version and Date information.
Config Area
Place for general Document Settings and Parser behavior modifiers.
Body Area
Place for the Document Content.

All areas are optional. You can write a txt2tags document with just headers (such as our first example), or a document with no headers or settings.

The areas are delimited by special rules, which will be seen in detail on the next chapter. For now, this is a representation of the areas on a document:

             ____________
            |            |
            |   HEADERS  |       1. First, the Headers
            |            |
            |   CONFIG   |       2. Then the Settings
            |            |
            |    BODY    |       3. And finally the Document Body,
            |            |
            |    ...     |          which goes until the end
            |    ...     |
            |____________|

In short, this is how the areas are defined:

Headers First 3 lines of the file, or the first line blank for No Headers.
Config Begins right after the Header (4th or 2nd line) and ends when the Body Area starts.
Body The first valid text line (not comment or setting) after the Header Area.

Full Example

My nice doc Title
Mr. John Doe
Last Updated: %%mtime(%c)

%!target  : html
%!style   : fancy.css
%!encoding: UTF-8
%!options : --toc --enum-title

Hi! This is my test document.
Its content will end here.


Header Area

Location:

  • Fixed position: First 3 lines of the file. Period.
  • Fixed position: First line of the file if it is blank. This
means Empty Headers.

The Header Area is the only one that has a fixed position, line oriented. They are located at the first three lines of the source file.

These lines are content-free, with no static information type needed. But the following is recommended:

  • line 1: document title
  • line 2: author name and/or email
  • line 3: document date and/or version
(nice place for %%date)

Keep in mind that the first 3 lines of the source document will be the first 3 lines on the target document, separated and with high contrast to the text body (i.e. big letters, bold). If paging is allowed, the headers will be alone and centralized on the first page.

Less (or None) Header lines

Sometimes the user wants to specify less than three lines for headers, giving just the document title and/or date information.

Just let the 2nd and/or the 3rd lines empty (blank) and this position will not be placed at the target document. But keep in mind that even blanks, these lines are still part of the headers, so the document body must start after the 3rd line anyway.

The title is the only required header (the first line), but if you leave it blank, you are saying that your document has no headers. So the Body Area will begin right after, on the 2nd line.

No headers on the document is often useful if you want to specify your own customized headers after converting. The command line option --no-headers is usually required for this kind of operation.

Straight to the point

In short: "Headers are just positions, not contents"

Place one text on the first line, and it will appear on the target's first line. The same for 2nd and 3rd header lines.


Config Area

Location:

  • Begins right after the Header Area
    • Begins on the 4th line of the file if Headers were specified
    • Begins on the 2nd line of the file if No Headers were specified
  • Ends when the Body Area starts
    • Ends by a non Setting, Blank or Comment line

The Config Area is optional. An average user can write lots of txt2tags files without even know it exists, but the experienced users will enjoy the power and control it provides.

The Config Area is used to store document-specific settings, so you don't have to type them on the command line when converting the document. For example, you can set the default document target type and encoding.

Please read the Settings section for more information about them.


Body Area

Location:

  • Begins on the first valid text line of the file
    • Headers, Settings and Comments are not valid text lines
  • Ends at the end of the file (EOF)

The body is anything outside Headers and Config Areas.

The body holds the document contents and all formatting and structures txt2tags can recognize. Inside the body you can also put comments for TODOs and self notes.

You can use the --no-headers command line option to convert only the document body, suppressing the headers. This is useful to set your own headers on a separate file, then join the converted body.


Settings

Settings are special configurations placed at the source document's Config Area that can affect the conversion process. Their syntax is:

%! keyword : value

List of valid keywords:

Keyword Description
Target Set the default target to the document be converted to.
Options Set the default options to be used on the conversion. The format is the same as the command line options.
Style Set the document style. Used to define a CSS file for HTML/XHTML and to load a package in La Te X.
Encoding Set the document Character Set. Used if the document contains accented letters or other not-ASCII characters.
Pre Proc Input filter. Sets "find and replace" rules to be applied on the Body Area of the source document.
Post Proc Output filter. Sets "find and replace" rules to be applied on the converted document.

Example:

%!target  : html
%!options : --toc --toc-level 3
%!style   : fancy.css
%!encoding: UTF-8
%!preproc : "AMJ"        "Aurelio Marinho Jargas"
%!postproc: '&lt;BODY.*?&gt;'  '&lt;BODY bgcolor="yellow"&gt;'

Note that the spacing and capitalization of the keyword are ignored. So you can also do %!Target:html and %! TARGET :html.

Learn more about settings in Part VII - Mastering Settings.


Command Line Options

The fastest way of changing the txt2tags default behavior is to use command line options. This options are available on the Command Line Interface only, not on Gui or Web.

Just like the other system's tools, the program do accept a set of predefined options. An option is an hyphen followed by a letter or two hyphens followed by one or more words, like -t and --target.

Options that are generally used are --outfile to define a customized output file name, --toc to turn on the automatic TOC generation and --encoding to set the document character set. Most of the options can be turned off prefixing a "no-" before its name, for example: --no-encoding and --no-toc.

You can register the desired options for a source file inside its Config Area, using the %!options setting. This way you don't have to type them on the command line anymore. Example:

%!options: --toc -o mydoc.html

The exception is the target specification, that has its own setting:

%!target: html

Use the --help option to get a complete list of all the options available in txt2tags.

Learn more about %!options and %!target.


User Configuration File (RC File)

The user configuration file (also called RC file) is a central place to store the settings that will be shared by ALL converted files. If you keep inserting the same settings on every .t2t file you write, move it to the RC file and it will be used globally, for existing and future source files.

The default location of this file depends on your system. It can also be specified by the user, using an environment variable.

RC file location
Windows %HOMEPATH%\_t2trc
UNIX, Linux, Mac $HOME/.txt2tagsrc
User defined T2TCONFIG variable

The format of the settings is exactly the same as the ones used on the .t2t files Config Area. There is a sample RC file on the package at doc/txt2tagsrc. Example:

% my configs

%%% Always use CSS-friendly tags in HTML
%!options(html): --css-sugar

%%% Change the default TOC depth for all targets
%!options: --toc-level 4

%%% Set the default encoding for all documents
%!options: --encoding UTF-8

Any line that is not blank, a comment or a valid config line will raise error when txt2tags runs. So be careful when editing this file.

Txt2tags automatically apply the RC file contents into any source file it is converting. If you want to disable this behavior for a specific file, use the --no-rc command line option.

Configuration Loading Order and Precedence

There are three ways of telling txt2tags which options and settings to use, and this is the order that they are read and applied:

  1. The user configuration file (RC) settings
  2. The source document Config Area settings
  3. The command line options

First txt2tags reads the RC file contents (if any) and apply its configurations on the current source file. Then it scans the source document Config Area for settings and if found, they are applied also, overriding the RC ones in case of conflict. Finally comes the command line options, stronger than the other two.

So, if the document encoding was defined on the three resources, the command line will be the one used.


%!include command

The include command is used to paste the contents of an external file into the source document body. It is not a config, but a command, and it is valid on the document Body Area.

The include command is useful to split a large document into smaller pieces (like chapters in a book) or to include the full contents of an external file into the document source. Sample:

My first book
Dr. John Doe
1st Edition

%!include: intro.t2t
%!include: chapter1.t2t
%!include: chapter2.t2t
...
%!include: chapter9.t2t
%!include: ending.t2t

You just inform the filename after the %!include string. The optional target specification is also supported, so this is valid either:

%!include(html): file.t2t

Note that include will insert the file Body Area into the source document. The included file Header and Config Areas are ignored. This way you can convert the included file alone or inside the main document.

But there's another three types of include:

  • Verbatim include
  • Raw include
  • Tagged include

The Verbatim type includes a text file preserving its original spaces and formatting, just like if the text was inside the txt2tags Verbatim area (```). To specify this type, enclose the filename with backquotes:

%!include: ``/etc/fstab``

The Raw type includes a text file as is, not trying to find and parse txt2tags marks on it, just like if the text was inside the Raw area ("""). To specify this type, enclose the filename with double quotes:

%!include: ""nice_text.txt""

And the Tagged type is passed directly to the resulting document, with NO parsing or escaping performed by txt2tags. This way you can include additional tagged parts to your document. Useful for default header or footer information, or more complicated tagged code, unsupported by txt2tags:

%!include(html): ''footer.html''

Note that the filename is enclosed with single quotes. As the text inserted is already parsed, you should specify the target to avoid mistakes.


%!includeconf command

The includeconf command is used to include configurations from an external file into the current one. This command is valid inside the source document Config Area only.

It is useful to share the same config for multiple files, so you can centralize it. On any file do you want to include that central configuration, put a includeconf call. Example:

My First Document
John Doe
July, 2004

%!includeconf: config.t2t

Hi, this is my first document.

The format inside the included file is the same as in the RC file.

Note that the optional target specification is NOT supported for this command.

%!includeconf: config.t2t            &lt;--- OK
%!includeconf(html): config.t2t      &lt;--- NOT OK


Part V - Mastering Marks

Overview of all txt2tags marks:

Basic Beautifiers
Headers First 3 lines Bold words
Title = words = Italic //words//
Numbered title + words + Underline words
Paragraph words Strike --words--
Links [label url] Monospaced ``words``
Image [filename.jpg] Raw text ""words""
  Tagged text ''words''
Other
Quote <TAB>words Separator line --------...
List - words Strong line ========...
Numbered list + words Table   cell1 cell2 cell3...
Definition list : words Anchor = title =[anchor]
Comment line % comments Comment area %%%\n comments \n%%%
Verbatim line ``` word Verbatim area ```\n lines \n```
Raw line """ words Raw area """\n lines \n"""
Tagged line ''' words Tagged area '''\n lines \n'''

General Rules:

  • Headers are the first three document lines, marks are not interpreted.
  • Titles are balanced "=" or "+" chars around the title text. The more chars, more deep is the title.
  • Beautifiers don't accept spaces between the marks and its contents.
  • The Comment mark "%" must be at the line beginning (first column).
  • Images filename must end in GIF, JPG, PNG or similar.
  • The only multiline marks are the Comment, Verbatim, Raw and Tagged areas.
  • No mark is interpreted inside Verbatim, Raw and Tagged.
  • The Separator/Strong lines must have at least 20 chars.
  • Quote and lists (un)nesting is defined by indent.
  • A Table title line is defined by two || at the beginning of the line.


Headers

  • Description: Identifies the document headers
  • Properties: Multiline, Free Spaces, Align, Nesting
  • Contains: Macros
  • Syntax:
    • The first 3 lines of the source file.
    • Leave the first line blank to not specify headers at all.
Nice for command line one-liners or customized headers.
    • Leave the second and/or third lines blank to omit parts of header.
  • Details:
    • Marks are NOT interpreted
    • The first 3 lines will be the first 3 lines on the target document,
with high contrast to text body, or will be placed alone on the first page (if paging is allowed).
    • The headers are content-free, with no static information type
needed. But the following is recommended for the most documents:
      • Line 1: Document title
      • Line 2: Author name and/or email
      • Line 3: Document date and/or version (nice place for %%mtime)


Title, Numbered Title

  • Description: Identifies a (numbered or not) section title
  • Properties: Multiline, Free Spaces, Align, Nesting
  • Contains: -
  • Syntax:
    • For Numbered Title, just change "=" by "+" on the following rules
    • Balanced equal signs around, like this
    • More signs, more sublevels: title, =subtitle=,
==subsubtitle==, ...
    • There is a maximum of 5 levels, ====like this====
    • Unbalanced equals are not title, like this==
    • Free spacing inside the marks are allowed, =       like this  =
    • Titles can have an anchor =like this=[anchor]. To link to an anchor
create a [local link #anchor]
    • The anchor name can contain only letters, numbers, underscore
and hyphen (A-Za-z0-9_-)
  • Details:
    • Marks are NOT interpreted
    • Macros are NOT interpreted


Paragraph

  • Description: Identifies a paragraph of text
  • Properties: Multiline, Free Spaces, Align, Nesting
  • Contains: Macros, Beautifiers, Raw, Tagged, Links, Image, Comment
  • Syntax:
    • Paragraphs are groups of lines delimited by blank lines
    • Other blocks like lists, quote, table or verbatim also ends a
paragraph


Comment

  • Description: Used to insert text that will not appear on the target
document
  • Properties: Multiline, FreeSpaces, Align, Nesting
  • Contains: -
  • Syntax:
    • A line beginning with a percent char at the first column, % like this
    • NO leading spaces
  • Details:
    • As comments, they're not showed on the converted text
    • Not a block, so each comment line must begin with %
    • Useful for TODO and FIXME reminders and editor's notes


Comment Area

  • Description: Used to insert text that will not appear on the target
document
  • Properties: Multiline, FreeSpaces, Align, Nesting
  • Contains: -
  • Syntax:
    • A line with exactly 3 consecutive percents %%%, followed by
text lines, followed by another line with exactly 3 consecutive percents %%%
    • NO spaces allowed before or after the marks
  • Details:
    • As comments, they're not showed on the converted text
    • Useful for deactivate (not delete) large portions of the contents
    • If the end of the source file (EOF) is hit, the opened Comment Area
is closed


Bold, Italic, Underline, Strike

  • Description: Used to insert a bold/italic/underline/strike text inside a
paragraph, table, list or quote
  • Properties: Multiline, FreeSpaces, Align, Nesting
  • Contains: Macros, Beautifiers, Raw, Tagged, Links, Image
  • Syntax:
    • Two starts around for bold, **like this**
    • Two slashes around for italic, //like this//
    • Two underlines around for underline, __like this__
    • Two hyphens around for strike, --like this--
    • The marks must be glued with the contents (no spaces):
** this ** is invalid
  • Details:
    • All the beautified text must be on a single line of the source file,
no line breaks inside
    • Macros are allowed inside beautifiers: **%%date**
    • You can mix beautifiers one inside another,
""**__like__ //this//**""


Monospaced

  • Description: Used to insert a monospaced text inside a paragraph, table,
list or quote
  • Properties: Multiline, FreeSpaces, Align, Nesting
  • Contains: -
  • Syntax:
    • Two backquotes around, ``like this``
    • The marks must be glued with the contents (no spaces):
`` this `` is invalid
  • Details:
    • Marks are NOT interpreted
    • Macros are NOT interpreted
    • All the monospaced text must be on a single line of the source file,
no line breaks inside
    • In some targets, the internal spacing is maintained, in others the
consecutive spaces are squeezed to one
    • You can make a bold monospaced text enclosing it inside bold marks:
""**=monobold=**"". The same applies to the other beautifiers such as ""//=italic=//"" and ""__=underline=__"".


Verbatim Line, Verbatim Area

  • Description: Used to insert programming codes or other pre-formatted text,
preserving spacing and line breaks, and using a monospaced font
  • Properties: Multiline, FreeSpaces, Align, Nesting
  • Contains: -
  • Syntax: Verbatim Line:
    • A line beginning with 3 consecutive backquotes, followed by a space,
followed by the text, =""`="" like this``
    • The backquotes must be at the start of the line, no spaces before
  • Syntax: Verbatim Area:
    • A line with exactly 3 consecutive backquotes ```, followed by
text lines, followed by another line with exactly 3 consecutive backquotes ```
    • NO spaces allowed before or after the marks
  • Details:
    • Marks are NOT interpreted
    • Macros are NOT interpreted
    • If the end of the source file (EOF) is hit, the opened Verbatim Area
is closed


Separator Line, Strong Line

  • Description: Identifies a separator or strong line
  • Properties: Multiline, Free Spaces, Align, Nesting
  • Contains: -
  • Syntax:
    • The separator line can be composed by dashes "-" or underscores "_"
    • The strong line is composed by equals "="
    • Use at least least 20 dashes/underscores/equal signs
    • Optional spaces can be placed at the line start or end
    • Any other characters on the line invalidate the mark
  • Details:
    • If the target does not have separator line support, a commented line
is used instead
    • The strong line may have different behaviors on some targets:
      • A larger separator line
      • A pause on presentation formats, like Magic Point
      • A page break in paged targets, like La Te X


Links, Named Links

  • Description: Identifies a remote (Internet) or local link
  • Properties: Multiline, FreeSpaces, Align, Nesting
  • Contains: Macros, Raw, Tagged, Image
  • Syntax:
    • Any valid internet URL, ftp, news or email address is detected and
converted automatically
    • The protocol (http, https, ftp) is optional, www.likethis.com
    • A name can be used for a link: [click here www.url.com]
    • An image can point to a link: [[image.jpg] www.url.com]
    • Macros are allowed on the link address: [see source %%infile]
    • Macros are allowed on the link name: [mirror of %%outfile www.url.com]
    • All the link specification must be on a single line of the source
file, no line breaks inside
  • Details:
    • If the target does not have link support, they're just underlined


Quote

  • Description: Identifies a quoted (indented) line
  • Properties: Multiline, FreeSpaces, Align, Nesting
  • Contains: Macros, Beautifiers, Quote, Raw, Tagged, Bars, Links, Image, Comment
  • Syntax:
    • A line that starts with a tabulation (TAB) character
    • More TABs at the start increase the quote depth
    • Lists and tables are not allowed inside quote
  • Details:
    • If the end of the source file (EOF) is hit, the opened Quote is
closed
    • Some targets may not support quote nesting, then the subquotes lines
are moved up to the mother quote level.
    • There is not a limit for subquotes depth. But some targets may have
restrictions, so the subquotes than are deeper than the maximum level are moved up.


List, Numbered List, Definition List

  • Description: Identifies the start of a list item
  • Properties: Multiline, FreeSpaces, Align, Nesting
  • Contains: Macros, Beautifiers, Lists, Table, Verbatim, Raw, Tagged, Bars, Links, Image, Comment
  • Syntax:
    • A line that starts with a dash/plus/colon followed by exactly one
space
    • The first list char can NOT be a space (exception: definition
lists)
    • Optional spaces (regular spaces, not TAB) at the line beginning
define sublists depth (nesting)
    • Sublists end with a less depth item (from parent list) or with an
empty item
    • All opened lists are closed with two consecutive blank lines
  • Details:
    • If the end of the source file (EOF) is hit, all opened lists are
closed
    • Lists can be mixed, like a definition list inside a numbered list.
    • Some targets may not support list nesting, then the sublists items
are moved up to the mother list level.
    • There is not a limit for sublists depth. But some targets may have
restrictions, so the sublists than are deeper than the maximum level are moved up.


Image

  • Description: Identifies an image
  • Properties: Multiline, FreeSpaces, Align, Nesting
  • Contains: Macros
  • Syntax:
    • An image filename enclosed between brackets, [likethis.jpg]
    • The filename must end in an image extension like PNG, JPG, GIF,
... (case doesn't matter)
    • Symbols are allowed on the filename, [likethis!~1.jpg]
    • Macros are allowed on the filename, [report-%%date(%Y-%m-%d).png]
    • NO spaces allowed on the filename, [like this.jpg]
    • NO spaces allowed on the brackets, [ likethis.jpg ]
  • Details:
    • If the target does not have image support, the image filename is
shown inside (parenthesis).
    • The position of the mark on the line defines the image alignment:
      • [LEFT.jpg] blablablabla
      • blablablabla [CENTER.jpg] blablablabla
      • blablablabla [RIGHT.jpg]


Table

  • Description: Delimits a table row, with any number of columns
  • Properties: Multiline, Free Spaces, Align, Nesting
  • Contains: Macros, Beautifiers, Raw, Tagged, Links, Image, Comment
  • Syntax:
    • A leading pipe "|" identifies a table row
    • A leading double pipe "||" identifies a table title row
    • Leading spaces before first pipe identifies table centered align
    • The fields are separated by the " | " string (space pipe space)
    • A final pipe "|" at the first table row sets visible borders
    • A final pipe "|" at the other table rows are ignored (just cosmetic)
    • Closing a cell with more than one pipe "|" identifies column span:
"||" for 2 columns, "|||" for 3 and so on
    • Natural spaces inside each cell identifies its alignment
    • Example: | table | row | with | five | columns |
  • Details:
    • All the table row data must be on a single line of the source file,
no line breaks inside
    • Targets with column-oriented align (like sgml and La Te X), uses the
first table row align as the default for the other rows
    • Any non-table line closes the opened table, except comment lines
    • The cell count is flexible, each table row can have a different
number of cells
    • Currently there's no way to specify row span
    • If the target does not have table support, the table lines are
considered a Verbatim Area


Raw, Raw Line, Raw Area

  • Description: Used to "protect" some text from parsing, so marks and macros inside
it will not be expanded. But escapes are applied.
  • Properties: Multiline, FreeSpaces, Align, Nesting
  • Contains: -
  • Syntax: Raw:
    • Two double quotes around, ""like this""
    • Marks glued with the contents (no spaces)
  • Syntax: Raw Line:
    • A line beginning with 3 consecutive double quotes, """ like this
    • The double quotes must be at the start of the line, no spaces before
    • Use a space after the double quotes to separate them from the text
  • Syntax: Raw Area:
    • A line with exactly 3 consecutive double quotes, followed by text
lines, followed by another line with exactly 3 consecutive double quotes
    • NO spaces allowed before or after the marks
  • Details:
    • Marks are NOT interpreted
    • Macros are NOT interpreted
    • If the end of the source file (EOF) is hit, the opened Raw Area is
closed


Tagged, Tagged Line, Tagged Area

  • Description: Used to send text directly to the output, no parsing or escaping is made by txt2tags.
  • Properties: Multiline, FreeSpaces, Align, Nesting
  • Contains: -
  • Syntax: Tagged:
    • Two apostrophes around, ''like this''
    • Marks glued with the contents (no spaces)
  • Syntax: Tagged Line:
    • A line beginning with 3 consecutive apostrophes, ''' like this
    • The apostrophes must be at the start of the line, no spaces before
    • Use a space after the apostrophes to separate them from the text
  • Syntax: Tagged Area:
    • A line with exactly 3 consecutive apostrophes, followed by text
lines, followed by another line with exactly 3 consecutive apostrophes
    • NO spaces allowed before or after the marks
  • Details:
    • Marks are NOT interpreted
    • Macros are NOT interpreted
    • If the end of the source file (EOF) is hit, the opened Tagged Area is
closed
    • Use this mark to insert target code. For example, in HTML you could use
it to insert manual line breaks ''<br>'', custom DIVs ''<div id="myfooter">'' or even full blocks of code, like the Google Analytics tracking code.


Part VI - Mastering Macros

Macros are special purpose keywords, that are expanded on conversion time. They are used to insert dynamic information, for example the current date or information about the document source.

A macro is represented by the %% chars followed by its name, such as %%date. Some macros do accept an optional formatting string inside parenthesis, right after the macro name, such as %%date(%Y-%m-%d). This format string mixes common text with special directives, identified by a percent sign % followed by an identification character. If no format string is given, the default format is used.

Macro Name Expands to... Default Format
%%date The current date DONEm%d
%%mtime The source file modification time DONEm%d
%%infile The source file path %f
%%outfile The output file path %f
%%toc The document TOC (Table of Contents) -

General rules:

  • The macro name is case-insensitive, so %%date, %%DaTe and
%%DATE are identical
  • Macros are valid at the document Header Area and Body Area, except
%%toc that is valid on Body Area only
  • A macro starts the Body Area if it is found in the Config Area
  • A macro can be placed at any part of the line, including various per line
(except %%toc, valid when alone in a line)
  • A macro can be used inside links and images marks (except %%toc)
  • Macros are not expanded in Titles, Verbatim, Raw and Tagged Areas

Full example (bold text are expanded macros):

This is the Txt2tags User Guide, converted to tml by txt2tags from the userguide.t2t source file. The conversion was done at 2012-04-28 22:23:07, but the last change on the source document was made on 2012-04-28 17:55:23. Both source and converted file reside on the sources directory.


%%date

The %%date macro expands to the current date and time. It is very useful on the document headers or footer, to register the date when the document was generated. To expand to the source document last modification time, see the %%mtime macro.

This macros accepts several formatting directives. The full list can be found in the Python site. Here are the most commonly used:

Directive Description
%a Locale's abbreviated weekday name.
%A Locale's full weekday name.
%b Locale's abbreviated month name.
%B Locale's full month name.
%c Locale's appropriate date and time representation.
%d Day of the month as a decimal number [01,31].
%H Hour (24-hour clock) as a decimal number [00,23].
%I Hour (12-hour clock) as a decimal number [01,12].
%m Month as a decimal number [01,12].
%M Minute as a decimal number [00,59].
%p Locale's equivalent of either AM or PM.
%S Second as a decimal number [00,61]. (1)
%x Locale's appropriate date representation.
%X Locale's appropriate time representation.
%y Year without century as a decimal number [00,99].
%Y Year with century as a decimal number.
%% A literal "%" character.

Examples:

Macro --> Results for on 2012, Apr 28 at 22:23
%%date(Converted on: %c) --> Converted on: Sat Apr 28 22:23:07 2012
%%date(%Y-%m-%d) --> 2012-04-28
%%date(%I:%M %p) --> 10:23 PM
%%date(Today is %A, on %B.) --> Today is Saturday, on April.


%%mtime

The %%mtime macro expands to last modification time of the source document. It is useful to register when the file was last changed. This macro is a "sister" of the %%date macro, so it accepts exactly the same formatting directives.

As an example, this User Guide source file was last edited on Sat Apr 28 17:55:23 2012. This date was expanded from %%mtime(%c).


%%infile

The %%infile macro expands to the source file location on the system. It is useful to make those "_see the source of this file_" links on HTML pages. Providing such link is a friendly attitude with beginners, so they can use your source as a sample for their own page.

This macro accepts the following formatting directives:

%<char> Description Output for this User Guide source
%f File name userguide.t2t
%F File name (without extension) userguide
%e File extension t2t
%p Absolute file path /Users/thierry/Logiciels/txt2tags/sources/userguide.t2t
%d File path (directories only) /Users/thierry/Logiciels/txt2tags/sources
%D File path (parent dir only) sources
%% Literal percent char %

Examples:

Source --> Expanded
This Guide parent dir is %%infile(%D). --> This Guide parent dir is sources.
I do use the %%infile(%e) file extension. --> I do use the t2t file extension.
[See the source %%infile] --> See the source
Converted to XHTML, I'll be %%infile(%F).xhtml --> Converted to XHTML, I'll be userguide.xhtml

Note: The macro is expanded to "-" if the source file is STDIN.


%%outfile

The %%outfile macro expands to the converted file location on the system. It is useful to its name inside the document Body or Headers. This macro is a sister of the %%infile macro and do accept exactly the same formatting directives.

Examples:

Source --> Expanded
You are reading the %%outfile file. --> You are reading the userguide.tml file.
txt2tags -t %%outfile(%e) -i %%infile -o %%outfile --> txt2tags -t tml -i userguide.t2t -o userguide.tml

Note: The macro is expanded to "-" if the output file is STDOUT.


%%toc

The %%toc macro expands to the document's Table of Contents. It is useful for you to specify exactly where you want the TOC to be placed. You can even use the macro more than one time and place the TOC at the end of the document also, for example. This Guide is using %%toc to position the TOC.

Different from the other macros, this one does not accept a format string and has its own special rules:

  • Valid at the document Body Area only
  • Must be alone on the line (leading and trailing spaces are allowed)
  • Must be used together with --toc command line option, or it will be
ignored
  • The default automatic TOC positioning/formatting is disabled when a
%%toc is found


Part VII - Mastering Settings

Settings are special configurations placed at the source document's Config Area that can affect the conversion process. The Settings are all optional. The average user can live fine without them. But they are addictive, if you start using them, you'll never stop smile

Setting lines are special comment lines, marked by a leading identifier ("!") that makes them different from plain comments. The syntax is just as simple as variable setting, composed by a keyword and a value, separated from each by a colon (":").

%! keyword : value

Syntax details:

  • The exclamation mark must be placed together with the comment char
(%!), no spaces between them.

  • The spaces around the keyword and the separator are optional.

  • Keywords are case insensitive (case doesn't matter).

Rules:

  • Settings are valid only inside the Config Area, and are considered
plain comments if found on the document Body.

  • If the same keyword appears more than one time on the Config Area, the
last found will be the one used. Exception: options, preproc and postproc, which are cumulative.

  • A setting line with an invalid keyword will be considered a plain
comment line.

  • This settings have precedence over RC file, but not on command line
options.


%!target

Using the target setting, a default target format is defined for the document:

%!target: html

This way the user can just call

$ txt2tags file.t2t

And the conversion will be done, to the specified target.

The target setting does not support optional target specification. That doesn't make sense, such as %!target(tex): html.


%!options

Writing long command lines every time you need to convert a document is boring and error prone. The Options setting let the user save all the converting options together with the source document. This also ensures that the document will always be converted the same way, with the same options.

Just write it with no syntax errors, as you were on the real command line. But omit the "txt2tags" program call on the beginning, the target specification and the source filename from the ending.

For example, if you do use this command line to convert your document:

$ txt2tags -t html --toc --toc-level 2 --enum-title file.t2t

You can save yourself from typing pain using this Options setting inside the document source:

%!target: html
%!options(html): --toc --toc-level 2 --enum-title

Now the options are registered inside the source file, so you can convert it with this simple command:

$ txt2tags file.t2t

Tip for Vim users: To convert the document right inside the editor, just run :!txt2tags %


%!encoding

The Encoding setting is needed by non-english writers, who uses accented letters and other locale specific details, so the target document Character Set must be customized (if allowed).

The valid values for the Encoding setting are the same charset names valid for HTML documents, like iso-8859-1 and koi8-r. If you're not sure which encoding you should use, try utf-8. If that doesn't work, this complete (and long!) list should help.

The La Te X target uses alias names for encoding. This is not a problem for the user, because txt2tags translate the names internally. Some examples:

txt2tags/HTML > LaTeX
windows-1250 >>> cp1250
windows-1252 >>> cp1252
ibm850 >>> cp850
ibm852 >>> cp852
iso-8859-1 >>> latin1
iso-8859-2 >>> latin2
koi8-r >>> koi8-r

If the value is unknown to txt2tags, it will be passed "as is", allowing the user to specify custom encodings.


%!preproc

The Pre Proc is an input filter that changes the Body Area of the source document. It is a "find and replace" feature, applied right after the line is read from the document source, before any parsing by txt2tags.

It is useful to define some abbreviations for common typed text, as:

%!preproc: JJS          "John J. Smith"
%!preproc: RELEASE_DATE "2003-05-01"
%!preproc: BULLET       "[images/tiny/bullet_blue.png]"

So the user can write a line like:

Hi, I'm JJS. Today is RELEASE_DATE.

And txt2tags will "see" this line as:

Hi, I'm John J. Smith. Today is 2003-05-01.

This filter is a component that acts between the document author and the txt2tags conversion. It's like a first conversion before the "real" one. This behavior is similar to an external Sed/Perl filter, called this way:

$ cat file.t2t | preproc-script.sh | txt2tags -

So the txt2tags parsing will begin after all the Pre Proc substitutions were applied.

Note: Remember that the preprocessing is applied only to the BODY of the source document, not including the Header Area and Config Area.


%!postproc

The Post Proc is an output filter that changes the converted document. It is a "find and replace" feature, applied after all txt2tags parsing and processing is done.

It is useful to do some refinements on the generated document, change tags and add extra text or tags. Quick samples:

%!postproc(html): '&lt;BODY.*?&gt;' '&lt;BODY BGCOLOR="green"&gt;'
%!postproc(tex) : "\\newpage" ""

These filters change the background color of the HTML page and remove the page breaks on the La Te X target.

The Post Proc rules are just like an external Sed/Perl filter, called this way:

$ txt2tags -t html -o- file.t2t | postproc-script.sh &gt; file.html

Before this feature was introduced, it was very common to have little scripts to "adjust" the txt2tags results. These scripts were in fact just lots of sed (or alike) commands, to do "substitute this for that" actions. Now this replacement strings can be saved together with the document text, and the plus is to use the Python powerful Regular Expression machine to find patterns.


%!style

  • Useful in HTML and XHTML targets, it defines a CSS file for the target
document.

  • Useful in La Te X target, to load \usepackage modules.

  • The same effect is achieved with the command line option --style.

  • The --style option is stronger than %!style. If both are used, --style
wins.


Defining a Setting for a Specific Target

All the settings (except %!target) can be glued with a specific target using the %!key(target): value syntax. This way user can define different config for different targets.

This is specially useful in the pre/postproc filters, but is applicable to all settings. For example, defining different styles for HTML and La Te X:

%!style(html): fancy.css
%!style(tex) : amssymb

For the options setting it's very useful to adjust the converted document:

%!target: sgml
%!options(sgml): --toc
%!options(html): --style foo.css
%!options(txt ): --toc-only --toc-level 2

In this example, the default target is Sgml and it will use TOC. If the user run txt2tags -t html file.t2t, only the HTML options will be used, so the converted file will use "foo.css" style file and will have no TOC.


Details for Pre Proc and Post Proc Filters

  • Filters are a "find and replace" feature (think SED)

  • Filters do not follow the "last found, one used" schema, they're
cumulative. You can define as many filters as needed, with no limit. They will be applied on the same order as defined.

  • Different from other settings, both the target specific filters and
the generic ones (all targets) are used. On the following example, both filters are used on the HTML target:
%!postproc      :   this   that
%!postproc(html):   that   other

  • The filters must receive exactly TWO arguments

  • Special escapes as \n (line break) and \t (tabulation) are
interpreted

  • To delete some text, change it by an empty string
%!postproc: "undesired string" ""

  • To avoid problems, always use the explicit target form when using
Post Proc to change tags: %!postproc(target): <this> <that>

  • PREproc is applied right after the line is read, and POSTproc is
applied after all the parsing was made. This is similar to (UUOC ahead):
$ cat file.t2t | preproc.sh | txt2tags | postproc.sh

  • The first part of a filter (the "search for" part) is not read as a
regular string, but as a Regular Expression pattern. If you don't know what these expressions do, don't worry, you may never have to. Just keep in mind that you will need to "escape" some characters to use them. To escape is to prefix the character with a backslash "\". Here is the list:
\*  \+  \.  \^  \$  \?  \(  \)  \{  \[  \|  \\

  • Python Regular Expressions are available! They're similar to Perl
Regexes (PCRE). Example: Change all opening and closing "B" tags to "STRONG" on HTML:
%!postproc(html):   '(&lt;/?)B&gt;'   '\1STRONG&gt;'

  • The filter arguments can be passed on 3 ways:
    1. A single unquoted word such as FOO (no spaces)
    2. A string double quoted such as "FOO"
    3. A string single quoted such as 'FOO'

  • If your pattern has double quotes, protect it with single quotes and
vice-versa. Some valid samples:
%!postproc:   PATT    REPLACEMENT
%!postproc:  "PATT"  "REPLACEMENT"
%!postproc:  'PATT'  'REPLACEMENT'
%!postproc:   PATT   "REPLACEMENT"
%!postproc:  "PATT"  'REPLACEMENT'


Part VIII - Black Magic

This chapter is really not recommended for newbies. It demonstrates how to do strange things with txt2tags filters, abusing of complex patterns and Regular Expressions.

BEWARE! The following procedures are NOT encouraged and can break things. Even some text from the document source can be lost on the conversion process, not appearing on the target document. Just use these tactics if you really need them and know what you are doing.
Note: Filters are a powerful feature, but can be dangerous!
Note: Bad filters do generate unexpected results.

Keep that in mind, please.


Inserting Multiple Lines with %!postproc (such as CSS rules)

In filters, the replacement pattern can include multiple lines using the \n line break char.

This can be handy for including really short CSS rules on HTML target, with no need to create a separate file:

%!postproc: &lt;HEAD&gt;      '&lt;HEAD&gt;\n&lt;STYLE TYPE="text/css"&gt;\n&lt;/STYLE&gt;'
%!postproc: (&lt;/STYLE&gt;)  'body     { margin:3em               ;} \n\1'
%!postproc: (&lt;/STYLE&gt;)  'a        { text-decoration:none     ;} \n\1'
%!postproc: (&lt;/STYLE&gt;)  'pre,code { background-color:#ffffcc ;} \n\1'
%!postproc: (&lt;/STYLE&gt;)  'th       { background-color:yellow  ;} \n\1'

All the filters are tied to the first one, by replacing a string that it has inserted. So a single "<HEAD>" turns to:

&lt;HEAD&gt;
&lt;STYLE TYPE="text/css"&gt;
body     { margin:3em               ;}
a        { text-decoration:none     ;}
pre,code { background-color:#ffffcc ;}
th       { background-color:yellow  ;}
&lt;/STYLE&gt;


Creating "Target-Specific" Contents with %!preproc

Sometimes you need to insert some text on a specific target, but not on the others. This kind of strange behavior can be done using some Pre Proc tricks.

The idea is to insert this extra text on the document source as comments, but mark it in a way that a target-specific filter will "uncomment" those lines.

For example, if an extra paragraph must be added only in HTML target. Place the text as special comments, like this:

%html% This HTML page is Powered by [txt2tags http://txt2tags.org].
%html% See the source TXT file [here source.t2t].

As those lines start with %, they are plain comments lines and will be ignored. But when adding this special filter:

%preproc(html): '^%html% ' ''

The leading string is removed and those lines will be "activated", not being comments anymore. As a explicit target config, this filter will be processed for HTML targets only.


Changing Txt2tags Marks with %!preproc

Being a Regular Expressions guru, the user can customize the document source syntax, changing the txt2tags default marks to some he find more comfortable.

For example, a leading TAB is the Quotation mark. If the user doesn't like it, or his text editor has some strange relationship with TABs, he can define a new mark for Quoted text. Say a leading ">>> " was his choice. Then he will do this simple filter:

%!preproc: '^&gt;&gt;&gt; ' '\t'

And on the document source, the quoted text will be something like:

&gt;&gt;&gt; This is a quoted text.
&gt;&gt;&gt; The user defined this strange mark.
&gt;&gt;&gt; But they will be converted to TABs by PreProc.

Before the parsing begins, the strange ">>> " will be converted to TABs and txt2tags will recognize the Quote mark.

BEWARE! Extreme Pre Proc rules could eventually change the entire marks syntax, even generating conflicts between marks. Be really really careful when doing this.


The End

Thanks for reading! smile

http://txt2tags.org

Topic revision: r1 - 29 Apr 2012, ThierryPasquier
 
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