Easily set up devkitARM and ctrulib on systems supporting Bash. Git and Curl are required. `curl -sL https://git.io/vs2SL|sudo -E bash` to run the script, remove sudo to set up environment variables. Thanks to https://github.com/profi200 for the original script.

install.sh

#!/bin/bash

UPDATE=0
echo "devkitARM and ctrulib installer"
echo "script by s0r00t, original script by profi200"
if ! hash git 2>/dev/null; then
	echo "ERROR : Git is not installed. Please install Git."
	exit 1
fi
if ! hash gcc 2>/dev/null; then
	echo "ERROR : The GNU Compiler Collection is not installed. Please install GCC."
	exit 1
fi
if ! hash make 2>/dev/null; then
	echo "ERROR : GNU Make is not installed. Please install Make."
	exit 1
fi
echo "Running the Perl script..."
export DEVKITPRO=/opt/devkitpro
export DEVKITARM=$DEVKITPRO/devkitARM
curl -sL http://sourceforge.net/projects/devkitpro/files/Automated%20Installer/devkitARMupdate.pl/download | perl
cd /opt/devkitpro
if [ -d "ctrulib/libctru" ]; then
	UPDATE=1
	cd ctrulib/libctru
	echo "Updating libctru..."
	git pull
	echo "Done!"
else
	echo "Cloning libctru..."
	git clone https://github.com/smealum/ctrulib.git
	echo "Done!"
fi
cd ctrulib/libctru
echo "Building libctru..."
make
make install
echo "Done!"

if [ $UPDATE == 0 ]; then
	echo "devkitARM and ctrulib are now installed into /opt/devkitpro."
	if [[ $SHELL == *"bash"* ]]; then
		echo "Setting up environment variables for Bash..."
		echo "export DEVKITPRO=/opt/devkitpro" >> ~/.bashrc
	  	echo "export DEVKITARM=\$DEVKITPRO/devkitARM" >> ~/.bashrc
	  	echo "export PATH=\$PATH:\$DEVKITARM/bin" >> ~/.bashrc
	  	echo "Done!"
	  	exit
	fi
	if [[ $SHELL == *"fish"* ]]; then
		echo "Setting up environment variables for Fish..."
		echo "set -x DEVKITPRO /opt/devkitpro" >> ~/.config/fish/config.fish
	  	echo "set -x DEVKITARM \$DEVKITPRO/devkitARM" >> ~/.config/fish/config.fish
	  	echo "set -x PATH \$PATH \$DEVKITARM/bin" >> ~/.config/fish/config.fish
	  	echo "Done!"
	  	exit
	fi
	echo "Shell not recognized. Please set those environment variables for compilation to work :"
	echo "DEVKITPRO=/opt/devkitpro"
	echo "DEVKITARM=\$DEVKITPRO/devkitARM"
	echo "PATH=\$PATH:\$DEVKITARM/bin"
	exit
fi
echo "devkitARM and ctrulib are now updated."

is there another one of these for devkitPPC?