Gone FISHing

Let’s set the scene. You get to work, coffee in hand. Bright eyed and bushy tailed. For once you are keen to get stuck in, after all, that YAML isn’t going to munge itself. And then, it happens. The pain. You create a new terminal pane or a tmux split and wait. And wait. For the purposes of this story, anywhere between six and twelve seconds. Every. Single. Time. You. Split. Time stops. You can feel the energy leaving your body. Where once there was glorious synergy between man and computer, now there is rage.

TLDR; ZSH why u so slow

☝️I am aware that the TLDR came after the intro. It’s that kind of post.

After tolerating this for at least 30 seconds I became a very unwilling explorer of a hellscape of zsh profiling tools, plugin management frameworks and the like. Truly, this is a cursed timeline.

This is a blameless post, but I do wish to make it clear that culprit was found to be antigen, the ancien zsh plugin manager.

My plugins:

antigen bundle git
antigen bundle fzf
antigen bundle pyenv
antigen bundle zsh-users/zsh-syntax-highlighting
antigen bundle direnv
antigen bundle autojump
antigen bundle zsh-users/zsh-autosuggestions

Being a massive sucker for a sunk cost I then invested several irrecovable minutes of my life looking at other zsh plugin managers before realising that I hated what I’d become and should just sack off all this complicated zsh plugin malarky.

Except, some of that malarky is actually super useful

Saner heads prevailed and I decided to take a step back. What did I actually need from my shell?

• Gets out of my way
• Gets out of my way
• Does not take between six and twelve seconds to start
• Sane user experience defaults
• Reads my mind¹

Fortified with my list and a burning desire to not do any real work I headed off to investigate my options…

Chapter Two: 🐟

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Turns out that there are plenty of other shells out there - some really cool, new (to me), hip things like OIL or nushell; however, I landed straight away on Fish.

Getting Started

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On 🍎 devices with homebrew installing fish is simple: brew install fish

Changing the default shell is also a breeze:

# find out where your fish lives
which fish
/opt/homebrew/bin/fish

#TODO: write a joke about fishy hermit crabs
chsh -s /opt/homebrew/bin/fish

Configuring

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Fish has some interesting features, one of which is that it supports interactively updating Fish’s config.

For instance; adding homebrew installed applications to the user’s path:

# run me for profit
fish_add_path /opt/homebrew/bin

Fish config on a mac lives in ~/.config/fish/ by default. It supports conf.d for breaking apart or organising larger configurations

Aliases and Env variables

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Setting environment variables is simple; as before this may be done interactively or in your fish configuration files.

Here’s an example of adding the SSH_AUTH_SOCK env var for the 1password ssh agent:

set -x SSH_AUTH_SOCK ~/Library/Group\ Containers/2BUA8C4S2C.com.1password/t/agent.sock

Aliases are similarly simple:

# You didn't think we'd do a whole blog post
# without mentioning Kubernetes, did you?
alias k='kubectl'

Deep Sea Fishing

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So it’s safe to say that Fish became a usable Shell quite quickly for me. However, I’ve used BASH for over twenty years. I’m institutionalised.

Here’s a few helpers to make life a bit more bareable.

Last history item

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In BASH you can use !! to bring up the last history item. Here’s a similar implemention for Fish:

➜  cat functions/last_history_item.fish
#!/usr/bin/env fish

function last_history_item
    echo $history[1]
end

This can be called like so:

abbr -a !! --position anywhere --function last_history_item

Note that this is using a new feature, abbr. Sadly not a nordic pop band; abbrieviations are a way to have fish replace words with other words.

Hey, that sounds like aliases

You’d be right, but there are some differences. abbr shows the full command in your history, which is super handy and abbreviations are not expanded in scripts.

Moving up multiple directories

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Here’s an abbr for moving up two parent directories:

abbr -a ... --position command --function parent_of_parent

and the corresponding function:

#!/usr/bin/env fish

function last_history_item
    echo $history[1]
end

Note that these helper functions live in their own files:

➜  pwd
/Users/msh/.config/fish

➜  tree .
.
├── completions
│   ├── docker.fish -> /Applications/OrbStack.app/Contents/MacOS/../Resources/completions/docker.fish
│   ├── kubectl.fish -> /Applications/OrbStack.app/Contents/MacOS/../Resources/completions/kubectl.fish
│   └── tenv.fish
├── conf.d
│   ├── completions.fish
│   └── rustup.fish
├── config.fish
├── fish_variables
└── functions
    ├── last_history_item.fish
    ├── parent_of_parent.fish
    └── theme_gruvbox.fish

4 directories, 10 files

Chapter Three: Supplementing Fish

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I’ll maybe break these down in later posts; but to complete the setup I used the following:

zsh autojump replaced with zoxide.

fzf with shell history replaced with atuin.

starship for the prompt.

uv to replace pyenv.