ArtifiShell Intelligence

Makefile, man page, TOC and CSS tweaks for Pandoc Bash Blog

2020-04-17

I’ve added a few features to Pandoc Bash Blog since adding GoatCounter: some cosmetic, some useful, some very behind the scenes.

CSS tweaks

To separate code blocks more clearly from the rest of the text, they now have a darker background colour:

Code block with grey background

And to tell inline code better apart, it got some colour as well:

Coloured inline code

I first used the same grey background as for code blocks just like for example GitHub does for Markdown pages, but bumped into a snag; Pandoc believes that whitespace should be conserved for inline code and sets white-space: pre-wrap for code. This preserves whitespace, but still breaks lines; it does leave a blank at the end of the line, though, and with a visible background colour, that blank can be seen.

Visible extra blank at line end

So, a different font colour it was, and after looking at the defaults for a few CSS frameworks, I settled on #C7254E. Which keeps the blank, it’s just invisible now.

And finally, because I noticed that my amateur mess of font sizes resulted in tiny code in headings, I switched everything to relative font sizes using rems and ems, and in an exhaustive test of one browser on two screens, nothing looks fundamentally broken, so I declare that a success.

Before fix
After fix

YAML lint action

All those actions I wrote when a learned about GitHub Actions have generated quite a pile of YAML files: each action has one for metadata, and each workflow is in one. Since all the actions run on each other, that results in about a dozen or so YAML files floating around.

What’s more obvious than having yet another action to lint these as well? Run yamllint to the rescue!

The action wraps yamllint and works pretty much the same as the Run markdownlint action: the linter checks the whole repo, and an optional config file can be supplied. As for the Markdown linter, I fetch my own from my dotfiles.

Now I just have to update all my files because I recently enabled a new quoting rule…

My linting emoji are subject of another post

Anyway, I mention this here because Pandoc Bash Blog uses this action to lint its YAML files.

Makefile for installation

As a side effect of having grown from very minimal to slightly more involved, pbb used to make a bunch of assumptions about where specific files would live. At first, I just symlinked things like the style sheet from the pbb directory into this blog; later, I updated pbb init to symlink from the /usr/local hierarchy and the Bats test setup would actually copy things there.

Now, finally, there is a proper way to install pbb from scratch: a Makefile! I’m far from a Make expert, but let’s say I have seen worse than this. The file is “self-documenting” by way of parsing specifically formatted comments with Awk, offers a “dev mode” option to symlink instead of copy things, has an uninstall recipe, and respects the XDG Base Directory Specificiation. Or at least my personal flavour of it, combined with a sprinkle of the systemd file system hierarchy. Everything goes into ~/.local/share (or wherever $XDG_DATA_HOME points to), and the binary lives in ~/.local/bin, leaving both $HOME clutter free and allowing for non-sudo installation.

Since I’m not compiling anything, the Makefile is basically a weird shell script wrapper, but “use make install” just has such a nice ring to it.

I did realize that building the blog is actually a pretty good use case for a Makefile—rebuild those pages where the Markdown version is more recent—but that ship has sailed. Bash it is.

Optional table of contents

The TAOP summary is pretty long, so I thought it’d be useful to have a table of contents. Pandoc can create one, but I wanted it to be easy to control. There are a few knobs to turn, but I eventually figured out the correct ones.

Initially, I thought I can use either of the toc or table-of-contents metadata fields and set them to true in the YAML header of the post I want a TOC for. That didn’t work.

I was confused about the meaning of the variables. A glance at the default HTML template made things a little more clear:

$if(toc)$
<nav id="$idprefix$TOC" role="doc-toc">
$if(toc-title)$
<h2 id="$idprefix$toc-title">$toc-title$</h2>
$endif$
$table-of-contents$
</nav>
$endif$

They’re all different! toc serves to indicate if the TOC should be printed at all; table-of-contents actually contains the TOC. Aha. Setting toc: true in my post did give me an empty <nav> tag, but the table itself was missing.

As it turns out, the toc metadata variable and the --toc command line option are different as well. --toc is required to generate the table, and the toc variable controls if it is displayed or not. But now I got the TOC everywhere, and I wanted the default to be “no TOC”!

The last puzzle piece was to use a metadata file where I can set toc: false so the default is to not have a TOC; if I do want one, I can override the value in just the post where I want it. This also let me customize the heading used for the TOC by setting the toc-title variable.

Or at least that’s how I think everything works, but who knows. This post uses a TOC, just to show what it looks like.

A man page for pbb

Last, but not least, pbb now has a proper man page. It’s officially the official source of truth, other than the code itself, that is.

Not everybody considers writing documents using the man macros for roff exactly “thrilling” or “fun” or “not a waste of time”, but I kind of like it. It’s a bit like Markdown’s great-great-great-grandma! I keep hearing about mdoc being all the rage (mostly when I read anything written by its author) and “semantic” instead of just “presentation formatting”, but whenever I think of it, I’m already halfway through whatever I’m writing and promise myself to check it out next time.

I try and follow the Linux man page conventions as outlined by man-pages(7) regarding structure and style; the man page for the man macros man(7) and its longer cousin groff_man(7) come in handy to remind me of how to start a paragraph with a hanging tag (.TP!) and how to get pretty quotes (\*(lq and \*(rq!); the GNU roff short reference groff(7) is useful for all those non-man requests (new line? .br); and finally, if all else fails, there’s always the full-blown GNU troff manual.

There surely are a lot of man man pages.

In the end, all that counts is that going from this

The Zen of roff source

to this

The rendered man page

is super satisfying. To me.