Add install.zsh for standalone installs

install.zsh

@@ -0,0 +1,91 @@
+#!/usr/bin/env zsh
+
+error() {
+  echo "error: $*"
+  exit 1
+}
+
+directories=(
+  ~/.cache/zsh
+  ~/.local/bin
+  ~/.local/share/zsh/plugins
+  ~/.local/share/zsh/site-functions
+)
+
+for directory in $directories; do
+  mkdir -p $directory
+done
+
+plugins=(
+  zsh-users/zsh-autosuggestions
+  zsh-users/zsh-history-substring-search
+  zsh-users/zsh-syntax-highlighting
+  zsh-users/zsh-completions
+)
+
+for plugin in $plugins; do
+  plugin_name=${plugin/*\//}
+  plugin_directory=~/.local/share/zsh/plugins/$plugin_name
+  if [ -d $plugin_directory ]; then
+    if ! git -C $plugin_directory diff-index --quiet HEAD --; then
+      error $plugin_directory contains unstaged changes
+    fi
+    pull=`git -C $plugin_directory pull`
+    if [ "$pull" != "Already up-to-date." ]; then
+      echo changed pulled $plugin_directory
+    fi
+  else
+    git clone https://github.com/$plugin.git $plugin_directory > /dev/null
+    echo changed cloned $plugin_directory
+  fi
+  old_plugin_directory=~/.config/zsh/$plugin_name
+  if [ -d $old_plugin_directory ]; then
+    rm -rf $old_plugin_directory
+    echo changed removed $old_plugin_directory
+  fi
+done
+
+declare -A symlinks
+symlinks=(
+  ~/.config/zsh/zlogin ~/.zlogin
+  ~/.config/zsh/zlogout ~/.zlogout
+  ~/.config/zsh/zprofile ~/.zprofile
+  ~/.config/zsh/zshenv ~/.zshenv
+  ~/.config/zsh/zshrc ~/.zshrc
+  ~/.config/zsh/prompt_fresh_setup
+    ~/.local/share/zsh/site-functions/prompt_fresh_setup
+  ~/.config/zsh/cmake-uninstall ~/.local/bin/cmake-uninstall
+  ~/.config/zsh/$ ~/.local/bin/$
+  ~/.config/zsh/url/url ~/.local/bin/url
+)
+
+for completion in ~/.config/zsh/**/_*; do
+  filename=`basename $completion`
+  symlinks[$completion]=~/.local/share/zsh/site-functions/$filename
+done
+
+completions=( ~/.local/share/zsh/plugins/zsh-completions/src/* )
+for completion in $completions; do
+  filename=`basename $completion`
+  name=${filename:1}
+  if command -v $name > /dev/null; then
+    symlinks[$completion]=~/.local/share/zsh/site-functions/$filename
+  fi
+done
+
+for source in ${(k)symlinks}; do
+  dest=$symlinks[$source]
+  if [ -L $dest ]; then
+    target=`readlink $dest`
+    if [ "$target" != "$source" ]; then
+      rm $dest
+      ln -s $source $dest
+      echo changed replace incorrect symlink $dest
+    fi
+  elif [ -f $dest ]; then
+    error symlink failed $dest exists but is a regular file
+  else
+    ln -s $source $dest
+    echo changed created symlink $dest
+  fi
+done

zshrc

@@ -3,8 +3,12 @@
 
 # Load plugin scripts
 source-plugin() {
-  if [ -d ~/.config/zsh/$1 ]; then
-    source ~/.config/zsh/$1/$1.plugin.zsh
+  local shared_plugin=~/.local/share/zsh/plugins/$1/$1.plugin.zsh
+  local local_plugin=~/.config/zsh/$1/$1.plugin.zsh
+  if [ -f $shared_plugin ]; then
+    source $shared_plugin
+  elif [ -f $local_plugin ]; then
+    source $local_plugin
   else
     echo "zsh plugin not found: $1"
   fi