% pandoc % John MacFarlane % August 10, 2006 `pandoc` is a [Haskell] library for converting from one markup format to another, and a command-line tool that uses this library. It can read [markdown] and (subsets of) [reStructuredText], [HTML], and [LaTeX], and it can write [markdown], [reStructuredText], [HTML], [LaTeX], [RTF], and [S5] HTML slide shows. `pandoc`'s version of markdown contains some enhancements, like footnotes and embedded LaTeX. In contrast to existing tools for converting markdown to HTML, which use regex substitutions, `pandoc` has a modular design: it consists of a set of readers, which parse text in a given format and produce a native representation of the document, and a set of writers, which convert this native representation into a target format. Thus, adding an input or output format requires only adding a reader or writer. [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/ (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.) Recai Oktaş (roktas At debian.org) deserves credit for the build system, the debian package, and the robust wrapper scripts. [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 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/ ## Installing `pandoc` 1. Change to the directory containing the `pandoc` distribution. 2. Compile: make 3. See if it worked (optional, but recommended): make test 4. Install: make install Note: This installs `pandoc`, together with its wrappers and documentation, into the `/usr/local` directory, which requires root privileges. If you don't have root privileges or would prefer to install `pandoc` and the associated shell scripts into your `~/bin` directory, type this instead: PREFIX=~ make install-exec 5. Install Haskell libraries (optional): make install-lib 6. Install library documentation into `/usr/local/pandoc-doc` (optional): make install-lib-doc ## Removing `pandoc` Each of the installation steps described above can be reversed: make uninstall PREFIX=~ make uninstall-exec make uninstall-lib make uninstall-lib-doc # Using `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. For example, pandoc hello.txt will convert `hello.txt` from markdown to HTML. For other conversions, you must specify a reader and/or a writer using the `-r` and `-w` flags. To convert markdown to LaTeX, you would write: pandoc -w latex hello.txt To convert html to markdown: pandoc -r html -w markdown hello.txt Supported writers include `markdown`, `latex`, `html`, `rtf` (rich text format), `rst` (reStructuredText), and `s5` (which produces an HTML file that acts like powerpoint). Supported readers include `markdown`, `html`, `latex`, and `rst`. Note that the `rst` reader only parses a subset of reStructuredText 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 hello.txt > hello.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 (The `-s` option here tells `pandoc` to produce a standalone HTML file, with a proper header, rather than a fragment. For more details on this and many other command-line options, see below.) ## 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 some have additional requirements. (For example, `html2markdown` uses `tidy`, and `markdown2pdf` uses `pdflatex`.) 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`, `wget`, or an available text-based browser 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 `pdflatex`. Example: markdown2pdf mytextfile.txt creates a file `mytextfile.pdf`. # 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 `
` 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 `` 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 test-markdown`.) [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 `` tags around "First", "Second", or "Third"), while markdown puts `
` 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
*one* | [a link](http://google.com) |
one | a link |