Bash History Hacks

When you work a lot on the command line, history can be invaluable. I’ve lost count of the number of times I’ve forgotten how I ran some earlier command and used my bash history to find out what it was. This is one of the big advantages of using CLIs over GUIs.

Accessing history

The main interface I use to my history is ^P (Ctrl-P). This recalls the previous command from history. Subsequent presses step further back and ^N steps forward again. These keys are set in muscle memory at this point, I use them that much (they also work in emacs and many other places).

A Lament for the Firefox Quick Find Key

For as long as I’ve been a Firefox user—almost 20 years at this point—it has featured a “quick find” bound to the venerable / (forward slash) key.

Following a pattern established by other software like less, man, and vi the slash key was simple: it finds stuff in the current page.

Common patterns like this are great. It’s why everyone has agreed on what Ctrl-C and Ctrl-V (or very similar) should do across all operating systems. The / key used to be like this, but not any more.

Using Nerd Icons in Org Agenda

Org mode supports icons in its agenda views. The icons can be given as either file paths to images (like SVGs), as image data or as a display property. I use a Nerd Font along with the nerd-icons package in my Emacs config, so I thought I might as well enable icons in my org agenda views.

The nice thing about using nerd fonts is this works perfectly in text mode too (assuming you have a nerd font configured for your terminal emulator).

Custom Static Vector Maps on your Hugo Static Site

This blog is a static site built with Hugo. Being static means it can be served from a basic, standard (you might say stupid) web server with no server-side scripting at all. In fact, this blog is currently hosted on Github Pages, but it could be anywhere.

Up until now, if you wanted to include an interactive map on a static site you were limited to using an external service like Google Maps or Mapbox and embedding their JS into your page. This would then call to their non-static backend service to produce some kind of tiles for your frontend.

Working on Multiple Web Projects with Docker Compose and Traefik

Docker Compose is a brilliant tool for bringing up local development environments for web projects. But working with multiple projects can be a pain due to clashes. For example, all projects want to listen to port 80 (or perhaps one of the super common higher ones like 8000 etc.). This forces developers to only bring one project up at a time, or hack the compose files to change the port numbers.

I use the Unbound DNS resolver built in to pfSense. By default the resolver filters out any results that are private IP addresses. Normally this makes sense: no public domain should have a private address. But sometimes it does make sense. For example there are some useful services like sslip.io that will resolve to any IP address that you like. So 127.0.0.1.sslip.io resolves to to 127.0.0.1. This is can be useful for local development, especially when working with containers and reverse proxies and the like.

Why is Emacs Hanging?

Even after using Emacs for 15 years there’s still so much I can learn. I probably should have already known this, but there’s a first time for everything.

It’s rare that Emacs hangs. Exceedingly rare. Which is probably why I didn’t know how to deal with it. Today Emacs started hanging when trying to open files over a remote TRAMP session (SSH).

The most important key of all that everyone who uses Emacs knows is C-g. This is the universal “quit” key and it has the power to interrupt any long running processes. What I didn’t know about is M-x toggle-debug-on-quit. I’ve used toggle-debug-on-error extensively when programming Elisp (I even have it bound to a key in Elisp buffers). toggle-debug-on-quit is similar except the debugger is invoked when you C-g.

Replacing Strings in an Entire Project

This is a little trick I just applied and thought was cool enough to write down.

Let’s say you want to replace a name that is used throughout a project. Due to various conventions/restrictions in use the name might appear in several forms like: MY_COOL_NAME, my-cool-name, my_cool_name etc.

In Emacs you can invoke regexp replace across an entire project by invoking project-query-replace-regexp, by default bound to C-x p r. This will first prompt for the regexp to search for, then what to replace it with.

My 2023 Emacs Python Setup

I’ve been using Emacs for almost 15 years now. Somewhat surprisingly, I hadn’t touched my config in three years! It’s been working that well. But now that Emacs 29 has been released I’ve decided to take a look at what’s new and there have been some big changes, particularly for Python.

Goodbye Elpy, Goodbye Projectile

Elpy has been the primary mode for Python development for me for years now. But sadly, it looks like the project is no more. The good news is there are better ways to do what it did. It’s bittersweet to say goodbye to it and I will be eternally grateful to the authors, but progress is progress.

Install Calibre without Root

On Linux, software should generally be installed with your system package manager (apt, yum, portage etc.) However, Calibre is a bit “special” in this respect. While well-loved, it’s known to be a bit difficult to package (to say the least) and most distro packages you’ll find are out of date. The official website recommends against using any distro packages and instead installing it directly from the site.

Unfortunately, the official instructions are problematic for a number of reasons. For a start, copying and pasting commands from the browser is considered dangerous. But that’s easy to fix, in bash do Ctrl-X Ctrl-E and your preferred text editor will be opened for you to type your command. This means you can inspect what is pasted before is run (save the file then exit the editor to run the command). Very important. Always do this when copy/pasting from the web.