# Shells

### that alternative to GUIs in which you replace clicking-on-the-wrong-thing errors with typing-the-wrong-thing errors

The only thing worse than shell scripting is doing without shell scripting. Half a century on and we are still not great at bespoke automation of tasks. Unix-esque shell scripting is one passable methods for automation of some tasks, and the least awful for many, so you’d better learn it, or hire a personal assistant. Except the problem is that shell scripting is a ghastly quagmire of chaos, and, as usual, for the traditional variety of path-dependent reasons, the dominant players in the market have especially high chaos content in their quagmire.

“Shell” as I will lazily use it here may conflate several things, a scripting language, and a protocol for interacting with the system and displaying things on the screen (the “terminal”.) These all interact in complicated ways, especially on a modern system, but I’m going to brush over this nicety, because who gives a shit?1

## Your list of horrible alternatives

• bash is the default for most humans who must sojourn in this grim dale of automation. It has the virtues of having decades of careful crafting, and of ubiquity, and the vice of having decades of bitrot, accommodation to ill-considered primordial design choices, and of occasionally uploading all your personal data to online gangsters.

• fish has a strong fanbase and principled design. I am now using it. It’s no fancier than it claims to be, which is to say, a belated evolution in an old ecosystem. This is probably sufficient.

• dash is a less bloated bash clone, which by itself doesn’t seem advantage enough to sell it widely.

• zsh was a young turk to bash once, and may still be seen stomping about the internet, waving its walking cane and complaining about the benighted conservatism of that frightful old fart, bash.

• Plumbum brings a shell “feel” to python, and looks passionately maintained if not broadly used. As such it is the interactive version of one of many python system devops automation thingies such as ansible and kubernetes.

• xonsh uses a hybrid of python and bash syntax and has light dependencies plus the python standard library, as well as some light mockery of the design choices in plumbum.

• rush is here and there, too. Some kind of ruby-backed shell? I don’t know, my mind is wandering, Dave. Would you like me to sing you a song?

• neugram is a shell for go.

• Windows users have powershell, which sprang from Windows but now runs everywhere and is open source. It even looks good, although I won’t actually use it because of lock-in.

• There are many, many others, most of which only last a year or two before their maintainers resign and use bash. You too can roll your own vanity shell!

Idea: create shells cash, trash, theclash, and bangersandmash.

## General tips

### Switching shells

chsh -s which fish myusername

### Next-level piping

dgsh:

The directed graph shell, dgsh (pronounced /dæɡʃ/ — dagsh), provides an expressive way to construct sophisticated and efficient big data set and stream processing pipelines using existing Unix tools as well as custom-built components. It is a Unix-style shell (based on bash) allowing the specification of pipelines with non-linear non-uniform operations. These form a directed acyclic process graph, which is typically executed by multiple processor cores, thus increasing the operation’s processing throughput.

Go look at the website it has pretty DAGs.

fzf adds general fuzzy history search.

## Realistically you’re using bash; now what?

Try out some actual commands.

1. dedicated and wonderful developers from whose whose work I am grateful and humbled to benefit