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Zsh is a powerful shell that operates as both an interactive shell and as a scripting language interpreter. While being compatible with Bash (not by default, only if issuing emulate sh), it offers many advantages such as:

  • Efficiency
  • Improved tab completion
  • Improved globbing
  • Improved array handling
  • Full customisability

The Zsh FAQ offers more reasons to use Zsh.

This article was taken partly or wholly, with or without modification from: ArchWiki

Installation

Before starting users may want to see what shell is currently being used:

$ echo $SHELL

Install the zsh package. For syntax highlighting, install the zsh-syntax-highlighting package as well.

Initial configuration

Make sure that Zsh has been installed correctly by running the following in a terminal:

$ zsh

You should now see zsh-newuser-install, which will walk you through some basic configuration. If you want to skip this, press q. If you did not see it, you can invoke it manually with

$ zsh /usr/share/zsh/functions/Newuser/zsh-newuser-install -f

Making Zsh your default shell

See Command-line shell#Changing your default shell.

Tip: If replacing bash, users may want to move some code from ~/.bashrc to ~/.zshrc (e.g. the prompt and the aliases) and from ~/.bash_profile to ~/.zprofile (e.g. the code that starts the X Window System).

Configuration files

When starting Zsh, it'll source the following files in this order by default:

Note: By default, the /etc/zsh directory doesn't exist, and needs to be created
/etc/zsh/zshenv
This file should contain commands to set the global command search path and other system-wide environment variables; it should not contain commands that produce output or assume the shell is attached to a tty.
~/.zshenv
Similar to /etc/zsh/zshenv but for per-user configuration. Generally used for setting some useful environment variables.
/etc/zsh/zprofile
This is a global configuration file, it'll be sourced at login. Usually used for executing some general commands at login.
/etc/profile
This file should be sourced by all Bourne-compatible shells upon login: it sets up an environment upon login and application-specific (/etc/profile.d/*.sh) settings.
~/.zprofile
This file is generally used for automatic execution of user's scripts at login.
/etc/zsh/zshrc
Global configuration file, will be sourced when starting as a interactive shell.
~/.zshrc
Main user configuration file, will be sourced when starting as a interactive shell.
/etc/zsh/zlogin
A global configuration file, will be sourced at the ending of initial progress when starting as a login shell.
~/.zlogin
Same as /etc/zsh/zlogin but for per-user configuration.
/etc/zsh/zlogout
A global configuration file, will be sourced when a login shell exits.
~/.zlogout
Same as /etc/zsh/zlogout but for per-user configuration.


Global configuration files

For global configuration use /etc/zsh/zshrc, not /etc/zshrc. The same goes for /etc/zsh/zshenv, /etc/zsh/zlogin and /etc/zsh/zlogout. Note that these files are not installed by default, so create them if desired.

The only exception is zprofile, use /etc/profile instead.

Configure Zsh

Although Zsh is usable out of the box, it is almost certainly not set up the way most users would like to use it, but due to the sheer amount of customization available in Zsh, configuring Zsh can be a daunting and time-consuming experience.

Simple .zshrc

Included below is a sample configuration file, it provides a decent set of default options as well as giving examples of many ways that Zsh can be customized. In order to use this configuration save it as a file named .zshrc.

Tip: Apply the changes without needing to logout and then back in by running source ~/.zshrc

Here is a simple .zshrc:

~/.zshrc
autoload -U compinit promptinit
compinit
promptinit

# This will set the default prompt to the walters theme
prompt walters

Configuring $PATH

In short, put the following in ~/.zshenv:

~/.zshenv
typeset -U path
path=(~/bin /other/things/in/path $path[@])

See also A User's Guide to the Z-Shell and the note in #Configuration files.

Command completion

Perhaps the most compelling feature of Zsh is its advanced autocompletion abilities. At the very least, enable autocompletion in .zshrc. To enable autocompletion, add the following to your ~/.zshrc:

~/.zshrc
autoload -U compinit
compinit

The above configuration includes ssh/scp/sftp hostnames completion but in order for this feature to work, users need to prevent ssh from hashing hosts names in ~/.ssh/known_hosts.

Warning: This makes the computer vulnerable to "Island-hopping" attacks. In that intention, comment the following line or set the value to no:
/etc/ssh/ssh_config
#HashKnownHosts yes

And move ~/.ssh/known_hosts somewhere else so that ssh creates a new one with un-hashed hostnames (previously known hosts will thus be lost). For more information, see the SSH readme for hashed-hosts.

For autocompletion with an arrow-key driven interface, add the following to:

~/.zshrc
zstyle ':completion:*' menu select
To activate the menu, press tab twice.

For autocompletion of command line switches for aliases, add the following to:

~/.zshrc
setopt completealiases

The "command not found" hook

See Pkgfile#Command not found.

Preventing duplicate lines in the history

To ignore duplicate lines in the history, use the following:

~/.zshrc
setopt HIST_IGNORE_DUPS

To free the history from already created duplicates, run:

$ sort -t ";" -k 2 -u ~/.zsh_history | sort -o ~/.zsh_history

The ttyctl command

[1] describes the ttyctl command in Zsh. This may be used to "freeze/unfreeze" the terminal. Many programs change the terminal state, and often do not restore terminal settings on exiting abnormally. To avoid the need to manually reset the terminal, use the following:

~/.zshrc
ttyctl -f

Key bindings

Zsh does not use readline, instead it uses its own and more powerful zle. It does not read /etc/inputrc or ~/.inputrc. Zle has an emacs mode and a vi mode. By default, it tries to guess whether emacs or vi keys from the $EDITOR environment variable are desired. If it is empty, it will default to emacs. Change this with bindkey -e or bindkey -v respectively for emacs mode or vi mode.

See also zshwiki: bindkeys.

Bind key to ncurses application

Bind a ncurses application to a keystoke, but it will not accept interaction. Use BUFFER variable to make it work. The following example lets users open ncmpcpp using Alt+\:

~/.zshrc
ncmpcppShow() { BUFFER="ncmpcpp"; zle accept-line; }
zle -N ncmpcppShow
bindkey '^[\' ncmpcppShow

Alternate way to bind ncurses application

This method will keep everything you entered in the line before calling application

~/.zshrc
ncmpcppShow() { ncmpcpp <$TTY; zle redisplay; }
zle -N ncmpcppShow
bindkey '^[\' ncmpcppShow

File manager key binds

Key binds like those used in graphic file managers may come handy. The first comes back in directory history (Alt+Left), the second let the user go to the parent directory (Alt+Up). They also display the directory content.

~/.zshrc
cdUndoKey() {
  popd      > /dev/null
  zle       reset-prompt
  echo
  ls
  echo
}

cdParentKey() {
  pushd .. > /dev/null
  zle      reset-prompt
  echo
  ls
  echo
}

zle -N                 cdParentKey
zle -N                 cdUndoKey
bindkey '^[[1;3A'      cdParentKey
bindkey '^[[1;3D'      cdUndoKey

History search

Add these lines to .zshrc

~/.zshrc
[[ -n "${key[PageUp]}"   ]]  && bindkey  "${key[PageUp]}"    history-beginning-search-backward
[[ -n "${key[PageDown]}" ]]  && bindkey  "${key[PageDown]}"  history-beginning-search-forward

Doing this, only past commands beginning with the current input would have been shown.

Prompts

There is a quick and easy way to set up a colored prompt in Zsh. Make sure that prompt is set to autoload in .zshrc. This can be done by adding these lines to:

~/.zshrc
autoload -U promptinit
promptinit

Available prompts are listed by running the command:

$ prompt -l

For example, to use the prompt walters, enter:

$ prompt walters

To preview all available themes, use this command:

$ prompt -p

Customizing the prompt

For users who are dissatisfied with the prompts mentioned above (or want to expand their usefulness), Zsh offers the possibility to build a custom prompt. Zsh supports a left- and right-sided prompt additional to the single, left-sided prompt that is common to all shells. Customize it by using PROMPT= with the following variables:

See Prompt Expansion for a list of prompt variables and conditional substrings.

Colors

Zsh sets colors differently than Bash. Add autoload -U colors && colors before PROMPT= in .zshrc to use them. Usually you will want to put these inside %{ [...] %} so the cursor does not move.

Command Description
$fg[color] will set the text color (red, green, blue, etc. - defaults to whatever format set prior to text)
%F{color} [...] %f effectively the same as the previous, but with less typing. Can also prefix F with a number instead.
$fg_no_bold[color] will set text to non-bold and set the text color
$fg_bold[color] will set the text to bold and set the text color
$reset_color will reset the text color to the default color. Does not reset bold. use %b to reset bold. Saves typing if it's just %f though.
%K{color} [...] %k will set the background color. Same color as non-bold text color. Prefixing with any single-digit number makes the bg black.
Possible color values
black or 0 red or 1
green or 2 yellow or 3
blue or 4 magenta or 5
cyan or 6 white or 7
Note: Bold text does not necessarily use the same colors as normal text. For example, $fg['yellow'] looks brown or a very dark yellow, while $fg_bold['yellow'] looks like bright or regular yellow.

Example

This is an example of a two-sided prompt:

PROMPT="%{$fg[red]%}%n%{$reset_color%}@%{$fg[blue]%}%m %{$fg_no_bold[yellow]%}%1~ %{$reset_color%}%#"
RPROMPT="[%{$fg_no_bold[yellow]%}%?%{$reset_color%}]"

And here's how it will be displayed:

username@host ~ %                                                         [0]

Dirstack

Zsh can be configured to remember the DIRSTACKSIZE last visited folders. This can then be used to cd them very quickly. You need to add some lines to your configuration file:

.zshrc
DIRSTACKFILE="$HOME/.cache/zsh/dirs"
if [[ -f $DIRSTACKFILE ]] && [[ $#dirstack -eq 0 ]]; then
  dirstack=( ${(f)"$(< $DIRSTACKFILE)"} )
  [[ -d $dirstack[1] ]] && cd $dirstack[1]
fi
chpwd() {
  print -l $PWD ${(u)dirstack} >$DIRSTACKFILE
}

DIRSTACKSIZE=20

setopt autopushd pushdsilent pushdtohome

## Remove duplicate entries
setopt pushdignoredups

## This reverts the +/- operators.
setopt pushdminus

Now use

dirs -v

to print the dirstack. Use cd -<NUM> to go back to a visited folder. Use autocompletion after the dash. This proves very handy if using the autocompletion menu.

Note: This will not work if you have more than one zsh session open, and attempt to cd, due to a conflict in both sessions writing to the same file.

Help command

Unlike bash, zsh does not enable a built in help command. To use help in zsh, add following to your zshrc:

autoload -U run-help
autoload run-help-git
autoload run-help-svn
autoload run-help-svk
unalias run-help
alias help=run-help

Fish-like syntax highlighting

Fish provides a very powerful shell syntax highlighting. To use this in zsh, you can install zsh-syntax-highlighting from offical repository and add following to your zshrc:

source /usr/share/zsh/plugins/zsh-syntax-highlighting/zsh-syntax-highlighting.zsh

Sample .zshrc files

Configuration Frameworks

  • Antigen - A plugin manager for zsh, inspired by oh-my-zsh and vundle.
  • oh-my-zsh is a popular, community-driven framework for managing your Zsh configuration. It comes bundled with a ton of helpful functions, helpers, plugins, themes.
  • Prezto - Instantly Awesome Zsh is a configuration framework for Zsh. It comes with modules, enriching the command line interface environment with sane defaults, aliases, functions, auto completion, and prompt themes.

Autostarting applications

Note: $ZDOTDIR defaults to $HOME

Zsh always executes /etc/zsh/zshenv and $ZDOTDIR/.zshenv so do not bloat these files.

If the shell is a login shell, commands are read from /etc/profile and then $ZDOTDIR/.zprofile. Then, if the shell is interactive, commands are read from /etc/zsh/zshrc and then $ZDOTDIR/.zshrc. Finally, if the shell is a login shell, /etc/zsh/zlogin and $ZDOTDIR/.zlogin are read.

See also the STARTUP/SHUTDOWN FILES section of man zsh.

Persistent rehash

Typically, compinit will not automatically find new executables in the $PATH. For example, after you install a new package, the files in /usr/bin would not be immediately or automatically included in the completion. Thus, to have these new exectuables included, one would run:

$ rehash

This 'rehash' can be set to happen automatically. Simply include the following in your zshrc:

~/.zshrc
zstyle ':completion:*' rehash true
Note: This hack has been found in a PR for Oh My Zsh [2]

Uninstallation

Change the default shell before removing the zsh package.

Warning: Failure to follow the below procedure may result in users no longer having access to a working shell.

Run following command:

$ chsh -s /bin/bash user

Use it for every user with zsh set as their login shell (including root if needed). When completed, the zsh package can be removed.

Alternatively, change the default shell back to Bash by editing /etc/passwd as root.

Warning: It is strongly recommended to use vipw when editing /etc/passwd as it helps prevent invalid entries and/or syntax errors.

For example, change the following:

username:x:1000:1000:Full Name,,,:/home/username:/bin/zsh

To this:

username:x:1000:1000:Full Name,,,:/home/username:/bin/bash

See also