path: root/README

% pandoc
% John MacFarlane
% August 10, 2006 

`pandoc` converts files from one markup format to another.  It can
read [markdown] and (with some limitations) [reStructuredText], [HTML], and
[LaTeX], and it can write [markdown], [reStructuredText], [HTML],
[LaTeX], [RTF], and [S5] HTML slide shows.  It is written in
[Haskell], using the excellent [Parsec] parser combinator library.

[markdown]: http://daringfireball.net/projects/markdown/
[reStructuredText]: http://docutils.sourceforge.net/docs/ref/rst/introduction.html
[S5]: http://meyerweb.com/eric/tools/s5/
[HTML]:  http://www.w3.org/TR/html40/
[LaTeX]:  http://www.latex-project.org/
[RTF]:  http://en.wikipedia.org/wiki/Rich_Text_Format
[Haskell]:  http://www.haskell.org/
[Parsec]:  http://www.cs.uu.nl/~daan/download/parsec/parsec.html

(c) 2006 John MacFarlane (jgm At berkeley.edu). Released under the
[GPL], version 2 or greater.  This software carries no warranty of
any kind.  (See LICENSE for full copyright and warranty notices.)

[GPL]: http://www.gnu.org/copyleft/gpl.html

# Installation

## Installing GHC

To compile `pandoc`, you'll need [GHC] version 6.4 or greater.  

If you don't have GHC already, you can get it from the 
[GHC Download] page.

[GHC]: http://www.haskell.org/ghc/
[GHC Download]: http://www.haskell.org/ghc/download.html

Note:  As of this writing, there's no MacOS X installer package for
GHC 6.4.2 (the latest version).  There is an installer for
GHC 6.4.1 [here](http://www.haskell.org/ghc/download_ghc_641.html#macosx).
It will work just fine on PPC-based Macs.  GHC has not yet been ported
to Intel Macs:  see <http://hackage.haskell.org/trac/ghc/wiki/X86OSXGhc>.

You'll also need standard build tools: GNU Make, sed, bash, and perl.
These are standard on unix systems (including MacOS X).  If you're
using Windows, you can install [Cygwin].

[Cygwin]: http://www.cygwin.com/

Note:  I have tested `pandoc` on MacOS X and Linux systems.  I have not
tried it on Windows, and I have no idea whether it will work on Windows.
  
## Installing `pandoc`

1.  Change to the directory containing the `pandoc` distribution.

2.  Compile:

            make

3.  Optional, but recommended:

            make test

4.  If you want to install the `pandoc` program and the relevant wrappers 
    and documents (including this file) into `/usr/local` directory, type:
            
            make install
    
    If you only want the `pandoc` program and the shell scripts `latex2markdown`,
    `markdown2latex`, `markdown2pdf`, `markdown2html`, `html2markdown` installed
    into your `~/bin` directory, type (note the **`-exec`** suffix):

            PREFIX=~ make install-exec

5.  If you want to install the Pandoc library modules for use in 
    other Haskell programs, type (as root):

            make install-lib
   
6.  To install the library documentation (into `/usr/local/pandoc-doc`), 
    type:

            make install-lib-doc
 
# Using `pandoc`

You can run `pandoc` like this:

    ./pandoc

If you copy the `pandoc` executable to a directory in your path
(perhaps using `make install`), you can invoke it without the "./":

    pandoc

If you run `pandoc` without arguments, it will accept input from
STDIN.  If you run it with file names as arguments, it will take input
from those files.  It accepts several command-line options.  For a
list, type

    pandoc -h

The most important options specify the format of the source file and
the output.  The default reader is markdown; the default writer is
HTML.  So if you don't specify a reader or writer, `pandoc` will
convert markdown to HTML.  To convert markdown to LaTeX, you could
write:

    pandoc -w latex input.txt

To convert html to markdown:

    pandoc -r html -w markdown input.txt

Supported writers include markdown, LaTeX, HTML, RTF,
reStructuredText, and S5 (which produces an HTML file that acts like
powerpoint).  Supported readers include markdown, HTML, LaTeX, and
reStructuredText.  Note that the rst (reStructuredText) reader only
parses a subset of rst syntax.  For example, it doesn't handle tables,
definition lists, option lists, or footnotes.  It handles only the
constructs expressible in unextended markdown.  But for simple
documents it should be adequate.  The LaTeX and HTML readers are also
limited in what they can do.  

`pandoc` writes its output to STDOUT.  If you want to write to a file,
use redirection:

	pandoc input.txt > output.html

Note that you can specify multiple input files on the command line.
`pandoc` will concatenate them all (with blank lines between them)
before parsing:

	pandoc -s chapter1.txt chapter2.txt chapter3.txt references.txt > book.html

## Character encoding

Unfortunately, due to limitations in GHC, `pandoc` does not
automatically detect the system's local character encoding.  Hence,
all input and output is assumed to be in the UTF-8 encoding.  If you
use accented or foreign characters, you should convert the input file
to UTF-8 before processing it with `pandoc`.  This can be done by
piping the input through [`iconv`]: for example,

	iconv -t utf-8 source.txt | pandoc > output.html

will convert `source.txt` from the local encoding to UTF-8, then
convert it to HTML, putting the output in `output.html`.

[`iconv`]: http://www.gnu.org/software/libiconv/

The shell scripts (described below) automatically convert the source
from the local encoding to UTF-8 before running them through `pandoc`.

## The shell scripts 

For convenience, five shell scripts have been included that make it
easy to run `pandoc` without remembering all the command-line options.
All of the scripts presuppose that `pandoc` is in the path, and
`html2markdown` also presupposes that `curl` and `tidy` are in the
path.

1.  `markdown2html` converts markdown to HTML, running `iconv` first to
	convert the file to UTF-8.  (This can be used as a replacement for
	`Markdown.pl`.)

2.	`html2markdown` can take either a filename or a URL as argument.  If
	it is given a URL, it uses `curl` to fetch the contents of the
	specified URL, then filters this through `tidy` to straighten up the
	HTML and convert to UTF-8, and finally passes this HTML to `pandoc` to
	produce markdown text:

	    html2markdown http://www.fsf.org

	    html2markdown www.fsf.org

	    html2markdown subdir/mylocalfile.html

3. 	`latex2markdown` converts a LaTeX file to markdown. 

	    latex2markdown mytexfile.tex

4. 	`markdown2latex` converts markdown to LaTeX:

	    markdown2latex mytextfile.txt

5.	`markdown2pdf` converts markdown to PDF, using LaTeX, but removing
	all the intermediate files created by LaTeX.  Example:

	    markdown2pdf mytextfile.txt

	creates a file `mytextfile.pdf` in the working directory.

# Command-line options

Various command-line options can be used to customize the output.  
For a complete list, type 

    pandoc --help  

`-p` or `--preserve-tabs` causes tabs in the source text to be
preserved, rather than converted to spaces (the default).

`--tabstop` allows the user to set the tab stop (which defaults to 4).  

`-R` or `--parse-raw` causes the HTML and LaTeX readers to parse HTML
codes and LaTeX environments that it can't translate as raw HTML or
LaTeX.  Raw HTML can be printed in markdown, reStructuredText, HTML,
and S5 output; raw LaTeX can be printed in markdown, reStructuredText,
and LaTeX output.  The default is for the readers to omit
untranslatable HTML codes and LaTeX environments.  (The LaTeX reader
does pass through untranslatable LaTeX commands, even if `-R` is not
specified.)

`-s` or `--standalone` causes `pandoc` to produce a standalone file,
complete with appropriate document headers.  By default, `pandoc`
produces a fragment.

`--custom-header` can be used to specify a custom document header.  To
see the headers used by default, use the `-D` option: for example,
`pandoc -D html` prints the default HTML header.

`-c` or `--css` allows the user to specify a custom stylesheet that
will be linked to in HTML and S5 output.

`-H` or `--include-in-header` specifies a file to be included
(verbatim) at the end of the document header.  This can be used, for
example, to include special CSS or javascript in HTML documents.

`-B` or `--include-before-body` specifies a file to be included
(verbatim) at the beginning of the document body (after the `<body>`
tag in HTML, or the `\begin{document}` command in LaTeX).  This can be
used to include navigation bars or banners in HTML documents.

`-A` or `--include-after-body` specifies a file to be included
(verbatim) at the end of the docment body (before the `</body>` tag in
HTML, or the `\end{document}` command in LaTeX).

`-T` or `--title-prefix` specifies a string to be included as a prefix
at the beginning of the title that appears in the HTML header (but not
in the title as it appears at the beginning of the HTML body).  (See
below on Titles.)

`-S` or `--smartypants` causes `pandoc` to produce typographically
correct HTML output, along the lines of John Gruber's [Smartypants].
Straight quotes are converted to curly quotes, `---` to dashes, and
`...` to ellipses.

[Smartypants]: http://daringfireball.net/projects/smartypants/

`-m` or `--asciimathml` will cause LaTeX formulas (between $ signs) in
HTML or S5 to display as formulas rather than as code.  The trick will
not work in all browsers, but it works in Firefox.  Peter Jipsen's
[ASCIIMathML] script is used to do the magic.

[ASCIIMathML]: http://www1.chapman.edu/~jipsen/mathml/asciimath.html

`-i` or `--incremental` causes all lists in S5 output to be displayed
incrementally by default (one item at a time).  The normal default
is for lists to be displayed all at once.  

`-N` or `--number-sections` causes sections to be numbered in LaTeX
output.  By default, sections are not numbered.

# `pandoc`'s markdown vs. standard markdown

In parsing markdown, `pandoc` departs from and extends [standard markdown]
in a few respects.  (To run `pandoc` on the official
markdown test suite, type `make markdown_tests`.)

[standard markdown]:  http://daringfireball.net/projects/markdown/syntax

## Lists

`pandoc` behaves differently from standard markdown on some "edge
cases" involving lists.  Consider this source: 

    1.  First
    2.  Second:
        -   Fee
        -   Fie
        -   Foe

    3.  Third

`pandoc` transforms this into a "compact list" (with no `<p>` tags
around "First", "Second", or "Third"), while markdown puts `<p>`
tags around "Second" and "Third" (but not "First"), because of
the blank space around "Third".  `pandoc` follows a simple rule:
if the text is followed by a blank line, it is treated as a
paragraph.  Since "Second" is followed by a list, and not a blank
line, it isn't treated as a paragraph.  The fact that the list
is followed by a blank line is irrelevant. 

## Literal quotes in titles

Standard markdown allows unescaped literal quotes in titles, as
in 

    [foo]: "bar "embedded" baz"

`pandoc` requires all quotes within titles to be escaped:

    [foo]: "bar \"embedded\" baz"

## Reference links

`pandoc` allows implicit reference links in either of two styles:

    1. Here's my [link]
    2. Here's my [link][]

    [link]: linky.com

If there's no corresponding reference, the implicit reference link
will appear as regular bracketed text.  Note: even `[link][]` will
appear as `[link]` if there's no reference for `link`.  If you want
`[link][]`, use a backslash escape: `\[link]\[]`.

## Footnotes

`pandoc`'s markdown allows footnotes, using the following syntax:

	here is a footnote reference,^(1) and another.^(longnote)

	^(1) Here is the footnote.  It can go anywhere in the document,
    except in embedded contexts like block quotes or lists.	

	^(longnote) Here's the other note.  This one contains multiple
	blocks.  
	^
	^ Caret characters are used to indicate that the blocks all belong
    to a single footnote (as with block quotes).
	^
	^ If you want, you can use a caret at the beginning of every line,
    ^ as with blockquotes, but all that you need is a caret at the
    ^ beginning of the first line of the block and any preceding 
    ^ blank lines.

Footnote references may not contain spaces, tabs, or newlines.

## Embedded HTML

`pandoc` treats embedded HTML in markdown a bit differently than
Markdown 1.0.  While Markdown 1.0 leaves HTML blocks exactly as they
are, `pandoc` treats text between HTML tags as markdown.  Thus, for
example, `pandoc` will turn

    <table>
        <tr>
            <td>*one*</td>
            <td>[a link](http://google.com)</td>
        </tr>
    </table>

into

    <table>
        <tr>
            <td><em>one</em></td>
            <td><a href="http://google.com">a link</a></td>
        </tr>
    </table>

whereas Markdown 1.0 will preserve it as is.  

There is one exception to this rule:  text between `<script>` and
`</script>` tags is not interpreted as markdown.

This departure from standard markdown should make it easier to mix
markdown with HTML block elements.  For example, one can surround
a block of markdown text with `<div>` tags without preventing it
from being interpreted as markdown.

## Title blocks

If the file begins with a title block

	% title
	% author(s) (separated by commas)
	% date

it will be parsed as bibliographic information, not regular text.  (It
will be used, for example, in the title of standalone LaTeX or HTML
output.)  The block may contain just a title, a title and an author,
or all three lines.  Each must begin with a % and fit on one line.
The title may contain standard inline formatting.  If you want to
include an author but no title, or a title and a date but no author,
you need a blank line:

	% My title
	% 
	% June 15, 2006

Titles will be written only when the `--standalone` (`-s`) option is
chosen.  In HTML output, titles will appear twice: once in the
document head -- this is the title that will appear at the top of the
window in a browser -- and once at the beginning of the document body.
The title in the document head can have an optional prefix attached
(`--title-prefix` or `-T` option).  The title in the body appears as
an H1 element with class "title", so it can be suppressed or
reformatted with CSS.

If a title prefix is specified with `-T` and no title block appears
in the document, the title prefix will be used by itself as the
HTML title.

## Box-style blockquotes

`pandoc` supports emacs-style boxquote block quotes, in addition to
standard markdown (email-style) boxquotes:

	,----
	| They look like this.
	`----

## Inline LaTeX

Anything between two $ characters will be parsed as LaTeX math.  The
opening $ must have a character immediately to its right, while the
closing $ must have a character immediately to its left.  Thus,
`$20,000 and $30,000` won't parse as math.  The $ character can be
escaped with a backslash if needed.

If you pass the `-m` (`--asciimathml`) option to `pandoc`, it will
include the [ASCIIMathML] script in the resulting HTML.  This will
cause LaTeX math to be displayed as formulas in better browsers.

[ASCIIMathML]: http://www1.chapman.edu/~jipsen/asciimath.html 

Inline LaTeX commands will also be preserved and passed unchanged
to the LaTeX writer.  Thus, for example, you can use LaTeX to
include BibTeX citations:

	This result was proved in \cite{jones.1967}.

You can also use LaTeX environments.  For example,

	\begin{tabular}{|l|l|}\hline
    Age & Frequency \\ \hline
	18--25  & 15 \\
    26--35  & 33 \\ 
    36--45  & 22 \\ \hline
	\end{tabular}

Note, however, that material between the begin and end tags will
be interpreted as raw LaTeX, not as markdown.

## Custom headers

When run with the "standalone" option (`-s`), `pandoc` creates a
standalone file, complete with an appropriate header.  To see the
default headers used for html and latex, use the following commands:

    pandoc -D html

    pandoc -D latex 

If you want to use a different header, just create a file containing
it and specify it on the command line as follows:

    pandoc --header=MyHeaderFile

# Producing S5 with `pandoc`

Producing an [S5] slide show with `pandoc` is easy.  A title page is
constructed automatically from the document's title block (see above).
Each section (with a level-one header) produces a single slide.  (Note
that if the section is too big, the slide will not fit on the page; S5
is not smart enough to produce multiple pages.)  

Here's the markdown source for a simple slide show, `eating.txt`:

	% Eating Habits
	% John Doe
	% March 22, 2005

	# In the morning

	- Eat eggs
	- Drink coffee

	# In the evening

	- Eat spaghetti
	- Drink wine

To produce the slide show, simply type

	pandoc -w s5 -s eating.txt > eating.html

and open up `eating.html` in a browser.  The HTML file embeds
all the required javascript and CSS, so no other files are necessary.

Note that by default, the S5 writer produces lists that display
"all at once."  If you want your lists to display incrementally
(one item at a time), use the `-i` option.  If you want a
particular list to depart from the default (that is, to display
incrementally without the `-i` option and all at once with the
`-i` option), put it in a block quote:

	> - Eat spaghetti
	> - Drink wine

In this way incremental and nonincremental lists can be mixed in
a single document.