Source: http://hackercodex.com/guide/install-fish-shell-mac-ubuntu/
The Fish shell goes where few command-line shells have gone before, shedding its forebearers’ POSIX baggage in favor of simplicity, consistency, and ease-of-use. Much like the Mac creators thought computers should be made to understand how humans work (and not the other way around), Fish observes your past behavior and suggests commands that it thinks you might be trying to execute. Sometimes, those suggestions are so spot-on that it can be downright spooky. Reactions of “How did Fish know that’s what I wanted to do?” are not uncommon.
In this article, we’re going to show how to install the recently-released Fish 2.1.0 on Mac OS X and Ubuntu, followed by some basic setup steps. Subsequent posts will cover more advanced configuration.
So can a command-line shell be Mac-like? Let’s find out.
Fish has a number of advantages over other shells:
- Fish suggests commands as you type based on history and completions, just like a web browser’s search bar
- Fish generates completions automatically by parsing your installed man pages
- Fish has a more intuitive syntax
- Fish has less historical baggage and technical debt
For additional background information, read:
- Can a command-line shell be Mac-like?
- Fish: the friendly interactive shell — as described in 2005 by the original author
There are several ways to install Fish on Mac OS X:
- traditional .pkg installer
- standalone Mac application
- Homebrew
- manual compilation
The first two options are available from the Fish web site and are straightforward enough to be considered self-explanatory.
That said, if you already use Homebrew (which I recommend) and have configured your environment as noted in the Mavericks Setup Guide, then you can install Fish as you would any other package:
brew install fish
Add Fish to /etc/shells, which will require an administrative password:
echo "/usr/local/bin/fish" | sudo tee -a /etc/shells
Make Fish your default shell:
chsh -s /usr/local/bin/fish
Now that Fish is installed, you can proceed to the Basic Configuration section below.
If you want to use the latest bleeding-edge version of Fish and already have Xcode installed, use the following steps to install from source:
git clone https://github.com/fish-shell/fish-shell ~/src/fish
cd ~/src/fish
xcodebuild install
ditto /tmp/fish.dst /
Add Fish to /etc/shells, which will require an administrative password:
echo "/usr/local/bin/fish" | sudo tee -a /etc/shells
Make Fish your default shell:
chsh -s /usr/local/bin/fish
Now that Fish is installed, you can proceed to the Basic Configuration section below.
On Ubuntu, the easiest way to keep up-to-date is via the offical PPA. If you prefer to install via .deb package, or if you want to install the bleeding-edge version of Fish from source, those instructions are further below.
The following steps will add the Fish 2.x PPA repository and install Fish:
sudo apt-add-repository ppa:fish-shell/release-2
sudo apt-get update
sudo apt-get install fish
Make Fish your default shell:
chsh -s /usr/bin/fish
Now that Fish is installed, you can proceed to the Basic Configuration section below.
The following steps are for the 64-bit version of Ubuntu 12.04 LTS. If you are using a different version of Ubuntu, you’ll need to retrieve an appropriate .deb package from the Fish on Linux page.
First retrieve and then install the .deb package:
wget http://fishshell.com/files/2.1.0/linux/Ubuntu/fish_2.1.0-1~precise_amd64.deb
sudo dpkg -i fish_2.1.0-1~precise_amd64.deb
Make Fish your default shell:
chsh -s /usr/bin/fish
Now that Fish is installed, you can proceed to the Basic Configuration section below.
If you prefer, you can keep up-to-date with the bleeding-edge version of Fish via the nightly build PPA. To do so, add the nightly PPA and install Fish:
sudo add-apt-repository ppa:fish-shell/nightly-master
sudo apt-get update
sudo apt-get install fish
Make Fish your default shell:
chsh -s /usr/bin/fish
Now that Fish is installed, you can proceed to the Basic Configuration section below.
Install dependencies:
sudo aptitude install build-essential git autoconf libncurses5-dev libncursesw5-dev gettext
Retrieve source, compile, and install:
mkdir -p ~/src
git clone https://github.com/fish-shell/fish-shell ~/src/fish
cd ~/src/fish
autoconf
./configure --without-xsel
make
sudo make install
Add Fish to /etc/shells:
echo "/usr/local/bin/fish" | sudo tee -a /etc/shells
Make Fish your default shell:
chsh -s /usr/bin/fish
Now that Fish is installed, you can proceed to the Basic Configuration section below.
The Fish shell should now be installed, but a bit more configuration will prove helpful later.
Create the Fish config directory:
mkdir -p ~/.config/fish
Create initial config file:
vim ~/.config/fish/config.fish
Initial config file contents, which adds /usr/local/bin to the PATH environment variable:
set -g -x PATH /usr/local/bin $PATH
Open a new terminal session, which should now load the Fish shell by default for the first time. You can enter help, followed by the return key, to load user documentation in your default browser.
You can also see your current configuration in your default browser by first entering this command:
fish_config
… and then visiting http://localhost:8000/ in your browser of choice.
Fish can parse your installed man pages and automatically generate completion files for your command-line tools. You should periodically run the following command to update those completions, which are stored in ~/.config/fish/completions by default:
fish_update_completions
Last but not least, running:
echo "set -g -x fish_greeting ''" >> ~/.config/fish/config.fish
… will eliminate the Fish welcome message that appears by default. If you want to add your own custom welcome message instead of removing the message entirely, insert your preferred text inside the '' marks.
If you want to temporarily switch to the Bash shell for a single session, run:
bash
When you are done with your Bash session, type exit to return to your Fish shell.
If you decide Fish isn’t for you and want to permanently revert your default shell back to Bash:
chsh -s /bin/bash
… will switch your default shell to Bash.
With Fish as your default shell, you may find that customizations you’ve made to your Bash environment are not present in Fish. The good news is that it’s easy to re-create those customizations — and create new enhancements — via Fish aliases and functions. The next article in this series will demonstrate some more advanced Fish capabilities, so stay tuned for more!
$PATH persistently