Perl Scripting

urxvt has a neat extensibility mechanism using Perl. This is bundled with most distros as urxvtperl or a similarly-named package (Ubuntu has rxvt-unicode bundled with some basic extensions). Apart from the fact that urxvt can display images (something I lean on in conjunction with the Ranger file browser), it's neat that one can customise it to the hilt as well using a bit of Perl (in fairness though, any and every tool these days has the ability to be "scripted", and Perl has carved itself into a somewhat niche corner dominated by [aging] Unix neck-beards). I would have preferred it to be able to be scripted using JavaScript or Python, but hey ... who's got time to knock up novel code these days anyway, right? (Well, as opposed to some wanton Google Fu cribbery).

(Dynamic) Font Sizing

As I get further into this article, I am becoming more aware of just how "last decade" I am ... I'm about to tout being able to change font size in urxvt on the fly as being something "neat". Of course, yes ... if whatever utility you build these days does not have the ability to dynamically modify font size (with instant feedback), well, then you may as well just go home. Never-the-less, I digress ...

To switch on the relevant Perl extension for urxvt for changing of the font size, a configuration item is required in .Xresources, as follows:

URxvt.perl-ext-common: font-size

You're going to have to restart any instances of urxvt you've got running for the changes to be seen. Then increasing and decreasing font size is a matter of C-+ and C-- respectively (that's "Control", not some variation of the language).