🐚 Fish shell features in zsh

A while back I wrote about why I switched to fish shell. But a lot of people don’t want to leave zsh — maybe they’ve been using it forever, have a big config they don’t want to rewrite, or just don’t want to deal with fish’s non-POSIX quirks. Fair enough!

The good news is that most of what I love about fish can be added to zsh with a few plugins. Here’s how.

1. Abbreviations

This is my favorite fish feature and the one I missed most when I had to use zsh. Fish expands abbreviations inline as you type — so gs becomes git status right in your prompt before you even hit enter.

Zsh doesn’t have this built in, but zsh-abbr does exactly the same thing:

# With Homebrew
brew install olets/tap/zsh-abbr

# Then add to ~/.zshrc
source $(brew --prefix)/share/zsh-abbr/zsh-abbr.zsh

Then add your abbreviations:

abbr gs="git status"
abbr gd="git diff"
abbr ga="git add"
abbr gc="git commit"
abbr gp="git pull origin $(current_branch)"
abbr gP="git push origin $(current_branch)"

Type gs and press Space and it expands to git status. Your history is readable, and when you’re pair programming your colleague can actually see what you’re doing.

If you already use Oh My Zsh, the built-in globalias plugin does something similar without any extra install.

2. Syntax highlighting

Fish colors your commands as you type — unknown programs show up in red so you know right away if you made a typo. zsh-syntax-highlighting brings that to zsh.

# With Homebrew
brew install zsh-syntax-highlighting

# Add to the END of ~/.zshrc (must be last or it won't work)
source $(brew --prefix)/share/zsh-syntax-highlighting/zsh-syntax-highlighting.zsh

One thing to watch out for: it has to be the last thing sourced in your .zshrc. If it’s not working, that’s probably why.

3. Oh My Zsh

Oh My Zsh is basically Oh My Fish but for zsh. It’s a framework for managing plugins, themes, and functions, and it’s honestly even more popular.

sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"

I have a current_branch function that returns the current git branch name, which I use in my abbreviations above. Here’s the zsh version:

# ~/.zshrc or ~/.oh-my-zsh/custom/functions.zsh
function current_branch() {
  ref=$(git symbolic-ref HEAD 2>/dev/null) || \
  ref=$(git rev-parse --short HEAD 2>/dev/null) || return
  echo ${ref#refs/heads/}
}

And kp to kill processes interactively using fzf:

function kp() {
  local pid
  pid=$(ps -ef | sed 1d | fzf -m | awk '{print $2}')
  [ -n "$pid" ] && echo $pid | xargs kill -${1:-9}
}

Oh My Zsh also has a bunch of themes that show your git branch, whether you have uncommitted changes, and other things right in your prompt.

4. Autocomplete

Fish shows a gray suggestion as you type based on your history and you just hit the right arrow to accept it. zsh-autosuggestions does the same thing.

# With Homebrew
brew install zsh-autosuggestions

# Add to ~/.zshrc
source $(brew --prefix)/share/zsh-autosuggestions/zsh-autosuggestions.zsh

One thing I actually prefer about zsh here: ctrl+r for history search works out of the box, no setup needed. In fish you have to wire it up manually.

If you want the fzf-powered version of ctrl+r anyway, add this after installing fzf:

source $(brew --prefix)/opt/fzf/shell/key-bindings.zsh

Final state of ~/.zshrc

All the source lines need to go in your ~/.zshrc. Zsh reads that file automatically every time you open a new terminal, so once it’s in there you never have to think about it again.

Here’s what your ~/.zshrc should look like with everything set up:

# Custom functions
function current_branch() {
  ref=$(git symbolic-ref HEAD 2>/dev/null) || \
  ref=$(git rev-parse --short HEAD 2>/dev/null) || return
  echo ${ref#refs/heads/}
}

function kp() {
  local pid
  pid=$(ps -ef | sed 1d | fzf -m | awk '{print $2}')
  [ -n "$pid" ] && echo $pid | xargs kill -${1:-9}
}

# Abbreviations
source $(brew --prefix)/share/zsh-abbr/zsh-abbr.zsh

abbr gs="git status"
abbr gd="git diff"
abbr ga="git add"
abbr gc="git commit"
abbr gp="git pull origin $(current_branch)"
abbr gP="git push origin $(current_branch)"

# Autosuggestions
source $(brew --prefix)/share/zsh-autosuggestions/zsh-autosuggestions.zsh

# fzf key bindings
source $(brew --prefix)/opt/fzf/shell/key-bindings.zsh

# Syntax highlighting — must be last
source $(brew --prefix)/share/zsh-syntax-highlighting/zsh-syntax-highlighting.zsh

After saving the file, run source ~/.zshrc once to apply everything to your current session. After that, new terminal windows will pick it all up automatically.

Why stay on zsh at all?

Zsh is POSIX-compatible, which means bash scripts just work. You don’t have to remember to type bash script.sh when a colleague shares a script with you. That’s the main thing fish can’t offer.

With the plugins above though, you’re really not giving much up.