Nathan Grigg

Reproducing Vim help as a fully cross-referenced PDF

It’s a long story, but for the last six months, I have been using Vim as my primary text editor. As I began to use Vim more often, I was frustrated by the lack of a tutorial that went beyond the basics. I finally found what I was looking for in Steve Losh’s Learn Vimscript the Hard Way, which is an excellent introduction to Vim’s power features. I also discovered the real reason there are no advanced tutorials, which is that everything you need to know is contained in Vim’s help files.

Vim’s documentation is incredibly complete and very useful. Unfortunately, it makes heavy use of cross references, and the cross references only work with Vim’s internal help viewer. I have no qualms about reading a reference document, but I would strongly prefer to do this kind of reading reclining on a couch with an iPad, rather that Control+F-ing my way through a read-only Vim buffer.

So I made it happen.

Choosing a format

I wanted a way to read and annotate the help files on my iPad. The files were available as HTML, but annotating HTML files is complicated. There are some apps that can annotate HTML, but there is no standard or portable way to do so.

I converted the HTML files to ePub using Calibre, but Vim’s help is very dependent on having lines that are 80 characters long. This caused problems in iBooks.

So instead, I settled on the old favorite, PDF. I can easily annotate a PDF on my iPad and then move those annotations to my computer or another device. Actually, the Vim documentation was already available in PDF format, but without the internal links.

To convert the Vim help files, which are specially-formated plain text, into a hyperlinked PDF, I started with Carlo Teubner’s HTML conversion script, which takes care of the syntax highlighting and linking. I just needed a way to programmatically make a PDF file.

Latex

Latex is clearly the wrong tool for the job. I don’t need the hyphenation or intelligent line breaking that Latex excels at. All I need is to display the text on a PDF page in a monospace font, preserving whitespace and line breaks. Latex ignores whitespace and line breaks.

But Latex is what I know, and I am very familiar with the hyperref package, which can make internal links for the cross references, so I used it anyway.

I used the fancyvrb package, which allows you to preserve whitespace and special characters, like the built-in verbatim environment does, but also allows you to use some Latex commands. This allowed me to do syntax highlighting and internal hyperlinks.

At one point, I ran into an issue where Latex was botching hyphenated urls. The good people at the Latex StackExchange site figured out how to fix it. The level at which they understand the inner workings of Tex amazes me.

The result

I produced an 11-megabyte, 2500-page monster that taught me enough to finally feel at home in Vim.