Gitdown is a simple tool for writing documentation hosted on a github repository. It uses ditaa to convert ascii diagrams into images, and produces markdown documents that can be uploaded to your repository along with code. I made Gitdown so that we could write technical white papers and user guides as plain text (including diagrams) and publish them with a single "git push" command. Gitdown is a simpler version of the tool we use to maintain the ØMQ Guide.
Gitdown is written and maintained by Pieter Hintjens. Please use the issue tracker for all comments and errata. This document was published on Wednesday October, 2010 at 11:40:52, and generated by the magic of Gitdown from README.txt.
This is version 2010.10.11 of Gitdown. Changelog:
- 2010.10.11: don't do symbol substitution in code blocks.
- 2010.10.09: added .toc token to generate table of contents.
License Installation and Use How it Works Gitdown Syntax Summary Markdown Syntax Summary
License -------Copyright (c) 2010 Pieter Hintjens Copyright (c) 1996-2010 iMatix Corporation
This is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.
Installation and Use --------------------The code is in the bin subdirectory. Here is how I install it on a new box:
sudo cp bin/* /usr/local/bin
export PERLLIB=$PATH # goes into .bash_profile
Gitdown includes Ditaa/0.9 and assumes that Ditaa goes into /usr/local/bin/ditaa0_9.jar. Feel free to propose a better design.
Gitdown assumes that these tools are already installed on your box, which is easy if you're running Linux:
- ImageMagick, specifically
mogrify. - Perl.
To use Gitdown, edit a text document much like this README.txt. Then:
gitdown myfile.txt
git add myfile.md images/
git commit -m "Hey, Gitdown is totally crazy!"
git push origin master
The images directory holds images for all documents in the current directory. You can write documents anywhere on the git tree but if they are not at the root you must tell Gitdown how to create a full image path by setting the SUBDIR symbol (see below).
How it Works ------------Gitdown exploits github.com's willingness to serve image blobs and Markdown documents that refer to them. This means you can publish a document with correctly-formatted links, together with images, in a single Git operation. It is a neat and comfortable way to work. Kudos to Stathis Sideris for making Ditaa. Gitdown also adds a preprocessing layer for symbolic insertion and simple macros like 'table of contents'. This code was recycled from htmlpp, a HTML preprocessor that looked a lot like Markdown.
The Gitdown workflow is:
- You edit a text file that contains text and diagrams in a single document.
- You process this document with Gitdown to give a Markdown document plus a number of images in an images subdirectory.
- You add the output (Markdown and images) to your commit set and push that to the repository.
- The Markdown document is now readable, with images, via the github.com user interface.
This README acts as an example.
Gitdown Syntax Summary ---------------------Gitdown is a pre-processor that adds these syntax elements on top of Markdown:
[diagram] Defines a ditaa diagram block
[/diagram] # represents diagram number 1..n
.- comment Comment line
.set name=value Sets Gitdown symbol
.sub oldval=newval Replaces oldval by newval in every line
.toc [top] Insert table of contents
.end Everything past this is ignored
$\(xxx) Value of variable, anywhere in text
$\(xxx?zzz) Value of variable, or zzz if undefined
%\(text?zzz) Value of environment variable, or zzz if undef
&abc\(text) Intrinsic function with arguments
time() Format current time as hh:mm:ss
date() Return current date value
date("picture") Format current date using picture
date("picture", date, lc) Format specified date using picture & language
week_day([date]) Get day of week, 0=Sunday to 6=Saturday
year_week([date]) Get week of year, 1 is first full week
julian_date([date]) Get Julian date for date
lillian_date([date]) Get Lillian date for date
date_to_days(date) Convert yyyymmdd to Lillian date
days_to_date(days) Convert Lillian date to yyyymmdd
future_date(days[,date]) Calculate a future date
past_date(days[,date]) Calculate a past date
date_diff(date1[,date2]) Calculate date1 - date2
image_height("image.ext") Get image height (GIF, JPEG)
image_width("image.ext") Get image width (GIF, JPEG)
file_size("filename",arg) Get size of file: optional arg K or M
file_date("filename") Get date of file
file_time("filename") Get time of file as hh:mm:ss
normalise("filename") Normalise filename to UNIX format
system("command") Call a system utility
lower("string") Convert string to lower case
upper("string") Convert string to upper case
The top argument for .toc tells it the top header level in the text. Lower levels are shown horizontally. E.g. this file has level 2 headers in the text and uses .toc 1 to get these laid-out on a single row.
These symbols have special meaning:
- GIT defines the root HTTP URL of the git repository
- BRANCH defines the respository branch, defaults to 'master'
- SUBDIR defines the /sub/dir to the current file, if not empty
These symbols are predefined by gitdown for you:
- INPUT specifies the original input file name.
- SELF specifies the input file name without extension.
- OUTPUT specifies the current output file name,
This is an extract of the most useful Markdown syntax.
# Header 1 or follow by ===== on next line
## Header 2 or follow by ----- on next line
### Header 3
#### Header 4
> Blockquote can continue over multiple lines
* List item can continue over multiple lines
1. List item can continue over multiple lines
code block indented 4 spaces
<url> automatic link, e.g. <ph@imatix.com>
 image link
[text](url) inline link
[text][] implicit reference link
[text]: url defined later in document
*emphasis* usually, italics
**strong** usually, bold
`Code` fixed-space font
- You can put HTML anywhere in your text.
- Blank lines separate paragraphs.
- For more details see the markdown syntax page.