Add configuration for zsh

- Add ~/.zshrc
  + Configure on how the `history` works
  + Enable nicer `cd` and globbing behavior
  + Enable tab completion, and make them feel nicer
  + Enable VI mode and add some VI-like key bindings
- Add ~/.zlogout clearing the screen
- Add ~/.config/zsh/.zshrc and make it dispatch to ~/.zshrc
  to make `zsh` use the same configuration even on more
  recent Debian/Ubuntu machines that do not look for
  ~/.zshrc any more
- Ensure ~/.local/state/zsh/ exists

.config/zsh/.zshrc

@@ -0,0 +1,10 @@
+#!/bin/zsh
+
+# Load the real `zsh` config file in ~/
+#
+# Recent Debian/Ubuntu versions look for .zshrc
+# in .config/zsh and no longer in ~/ which
+# is still the main location in many other distributions
+
+
+. "$HOME/.zshrc"

.config/zsh/README.md

@@ -0,0 +1,3 @@
+# `zsh`-related Configurations
+
+This folder contains files that are sourced by `zsh`.

.profile

@@ -51,6 +51,10 @@ if [ -n "$BASH_VERSION" ] && [ -f "$HOME/.bashrc" ]; then
 fi
 
 
+# `zsh`-specific configurations are automatically sourced from ~/.zshrc,
+# which then also ensures that this file is sourced
+
+
 # Put local executables on the `$PATH`
 _prepend_to_path "$HOME/.local/bin"
 

.zlogout

@@ -0,0 +1,3 @@
+#!/bin/zsh
+
+. "$XDG_CONFIG_HOME/shell/logout"

.zshrc

@@ -3,5 +3,78 @@
 # `zsh`-specific configurations
 
 
+# Remove built-in aliases because we use our own, sourced via ~/.profile
+unalias -a
+
+
 # Load configuration files common to all kinds of shells
 [ -f "$HOME/.profile" ] && . "$HOME/.profile"
+
+
+# Ensure `zsh` is running interactively
+[[ -o interactive ]] || return
+
+
+# Make `zsh` behave like `bash` for prompts
+PS1='%n@%m:%~%(!.#.$) '
+
+
+# Configure the `history`
+
+# Set these environment variables here
+# to avoid conflict/overlap with `bash`
+
+export HISTFILE="$XDG_STATE_HOME/zsh/history"
+export HISTSIZE=999999  # Number of lines kept in memory
+export SAVEHIST=999999  # Number of lines kept in the `$HISTFILE`
+
+setopt APPEND_HISTORY      # Do not overwrite the `$HISTFILE`
+setopt INC_APPEND_HISTORY  # Write to the `$HISTFILE` immediately
+setopt HIST_REDUCE_BLANKS  # Remove superfluous blanks from the `history`
+setopt HIST_VERIFY         # Show expanded `history` before executing
+
+
+# Make `zsh` feel even nicer
+
+setopt AUTO_CD         # Just type the directory to `cd` into it
+setopt EXTENDED_GLOB   # Advanced globbing patterns
+setopt NULL_GLOB       # Remove patterns with no matches
+setopt CORRECT         # Correct spelling of commands
+setopt CHECK_JOBS      # Show number of running jobs when exiting `zsh`
+setopt NO_BEEP         # Silence `zsh`
+
+
+stty -ixon             # Prevent Ctrl+S from freezing `zsh`
+
+
+# Enable (tab) completions
+
+autoload -Uz compinit && compinit
+
+# Enable match highlighting and scrolling through long lists,
+# and provide a different style of menu completion
+zmodload zsh/complist
+
+# Include hidden files in tab completion
+_comp_options+=(GLOB_DOTS)
+
+# Make selecting completions nicer with a visual menu
+zstyle ':completion:*' menu select
+
+# Make new executables completable right away
+zstyle ':completion:*' rehash true
+
+
+# Configure key bindings
+
+# VI mode
+bindkey -v
+
+# Use VI keys to navigate the completions in the menu
+bindkey -M menuselect 'h' vi-backward-char
+bindkey -M menuselect 'k' vi-up-line-or-history
+bindkey -M menuselect 'l' vi-forward-char
+bindkey -M menuselect 'j' vi-down-line-or-history
+
+# Enable Ctrl-R for reverse history search
+bindkey "^R" history-incremental-search-backward