HTMLDOC - HTML Conversion Software
HTMLDOC is a program that reads HTML and Markdown source files or web pages and generates corresponding EPUB, HTML, PostScript, or PDF files with an optional table of contents.
HTMLDOC was developed in the 1990's as a documentation generator for my previous company, and has since seen a lot of usage as a report generator embedded in web servers. However, it does not support many things in "the modern web", such as:
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Cascading Style Sheets (CSS): While I have experimented with adding CSS support to HTMLDOC, proper CSS support is non-trivial especially for paged output (which is not well supported by CSS)
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Encryption: HTMLDOC currently supports the older (and very insecure) PDF 1.4 (128-bit RC4) encryption. I have looked at supporting AES (256-bit) encryption, however it is not widely supported and there are incompatible changes in PDF 2.0, so it is unlikely to be added to HTMLDOC.
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Forms: HTML forms and PDF forms are very different things. While I have had many requests to add support for PDF forms over the years, I have not found a satisfactory way to do so.
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Tables: HTMLDOC supports HTML 3.2 tables with basic support for TBODY and THEAD.
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Unicode: While HTMLDOC does support UTF-8 for "Western" languages, there is absolutely no support for languages that require dynamic rewriting or right-to-left text formatting. Basically this means you can't use HTMLDOC to format Arabic, Chinese, Hebrew, Japanese, or other languages that are not based on latin-based alphabets that read left-to-right.
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Emoji: The fonts bundled with HTMLDOC do not include Unicode Emoji characters.
Resources
The following HTMLDOC resources are available online:
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Official web site and online documentation:
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Issue tracker and questions:
Using HTMLDOC
Note: Complete documentation for HTMLDOC is available in the "doc" subdirectory. The following provides basic information on using HTMLDOC at the command-line and does not discuss the GUI or web server functionality.
HTMLDOC accepts a list of HTML and/or Markdown "source" files and will generate EPUB, HTML, PostScript, or PDF output via command-line options. A summary of command-line options can be shown with the "--help" option:
htmldoc --help
HTMLDOC normally expects "structured" documents, with chapters, etc. Chapters begin with a H1 markup and continue to the end of the listed HTML files or the next H1 markup, whichever comes first. To convert unstructured documents such as web pages, use the "--webpage" option to HTMLDOC:
htmldoc --webpage ...
To generate a Level 2 PostScript file you might use:
htmldoc -f outfile.ps chapter1.html ... chapterN.html
Similarly you can generate an EPUB or PDF file of the same source files using:
htmldoc -f outfile.epub chapter1.html ... chapterN.html
htmldoc -f outfile.pdf chapter1.html ... chapterN.html
Finally, to generate HTML files for viewing (with a linked table-of-contents) do the following:
htmldoc -t html -d outdir chapter1.html ... chapterN.html
or:
htmldoc -t html -f outfile.html chapter1.html ... chapterN.html
A complete description of all command-line options and HTML guidelines can be found in the software users manual in the "doc" directory.
Credits
Many thanks to Leonard Rosenthol for providing the original changes to support a macOS (9) version of HTMLDOC.
The original table VALIGN and "HALF PAGE" code was contributed by D. Richard Hipp.
The original multiple header/footer image code was contributed by Lynn Pye.
The RC4 encryption code is from librc4 1.1 by the folks at Carnegie Mellon University.
The MD5 hash code is from L. Peter Deutsch at Aladdin Enterprises (creators of Ghostscript, among other things).
Legal Stuff
HTMLDOC is copyright © 1997-2022 by Michael R Sweet. This program is free software. Distribution and use rights are outlined in the file "COPYING".
HTMLDOC includes code to encrypt PDF document files using the RC4 algorithm with up to a 128-bit key. While this software and code may be freely used and exported under current US laws, other countries may restrict your use and possession of this code and software.
The Adobe Portable Document Format is Copyright 1985-2005 by Adobe Systems Incorporated. Adobe, FrameMaker, and PostScript are registered trademarks of Adobe Systems, Incorporated.
The Graphics Interchange Format is the copyright and GIF is the service mark property of CompuServe Incorporated.
Linux is a registered trademark of Linus Torvalds.
macOS is a registered trademark of Apple Inc.
Microsoft and Windows are registered trademarks of Microsoft Corporation.
UNIX is a registered trademark of the X/Open Company, Ltd.
This software is based in part on the work of the Independent JPEG Group and FLTK project.