Add package manager detection (partially)

zsh/zsh-setup.bash

@@ -1,21 +1,31 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Exit if there's an error
 set -e
-declare -A osInfo;
-osInfo[/etc/redhat-release]=yum
-osInfo[/etc/arch-release]=pacman
-osInfo[/etc/gentoo-release]=emerge
-osInfo[/etc/SuSE-release]=zypp
-osInfo[/etc/debian_version]=apt-get
-osInfo[/etc/alpine-release]=apk
 
-for f in ${!osInfo[@]}
-do
-    if [[ -f $f ]];then
-        PACKAGE_MANAGER=${osInfo[$f]}
-    fi
-done
+if [ $(whoami) != "root" ]; then
+    $SUDO = "sudo"
+    exit 1
+fi
+exit 0
+command_exists() { type "$1" &> /dev/null; }
 
-sudo ${PACKAGE_MANAGER} install zsh -y
+if command_exists "apt-get"; then
+    $SUDO apt-get install zsh -y
+elif command_exists "yum"; then
+    $SUDO apt-get install zsh -y
+elif command_exists "pacman"; then
+    $SUDO pacman -S zsh --noconfirm --needed
+elif command_exists "zypper"; then
+    $SUDO zypper install zsh -y
+elif command_exists "emerge"; then
+    $SUDO emerge --ask app-shells/zsh
+    $SUDO emerge --ask app-shells/zsh-completions
+    $SUDO emerge --ask app-shells/gentoo-zsh-completions
+elif command_exists "apk"; then
+    $SUDO apk add zsh -y;
+else
+    >&2 echo "Unsupported: unknown package manager"
+    exit 1
+fi
 
 cp -r zsh-files/* ~/