Install and switch between PHP versions (5.6, 7.0, and 7.1) using deb.sury.org packages

switch_php.sh

#!/bin/bash

# todo: support fpm as well as apache

# use bash "strict mode" http://redsymbol.net/articles/unofficial-bash-strict-mode/
set -euo pipefail
IFS=$'\n\t'

if [ $EUID -ne 0 ]; then
	echo "This script must be run as root" 
	exit 1
fi

if [ $# -eq 0 ]; then
	echo "Usage: switch_php <selected_version>"
	echo "where <selected_version> is either 5.6, 7.0, or 7.1"
	exit 1
fi

selected_version=$1

versions=(
	"5.6"
	"7.0"
	"7.1"
)

extensions=(
	"bcmath"
	"cli"
	"common"
	"curl"
	"dev"
	"gd"
	"intl"
	"json"
	"ldap"
	"mbstring"
	"mcrypt"
	"mysql"
	"opcache"
	"readline"
	"sqlite3"
	"tidy"
	"xml"
	"zip"
)

# install deb.sury.org package source as needed
if [ "$(apt-cache search php5.6 | wc -l)" -eq 0 ]; then
	apt-get -y install wget apt-transport-https lsb-release ca-certificates
	wget -O /etc/apt/trusted.gpg.d/php.gpg https://packages.sury.org/php/apt.gpg
	echo "deb https://packages.sury.org/php/ $(lsb_release -sc) main" > /etc/apt/sources.list.d/php.list
	apt-get update
fi

# purge any existing php5 packages from built-in packages
apt-get -y purge php5 php5-* libapache2-mod-php5
apt-get -y autoremove

# install deb.sury.org packages
for version in ${versions[@]}; do
	apt-get -y install "php$version" "libapache2-mod-php$version" "${extensions[@]/#/php$version-}"
done

# set selected version
update-alternatives --set php "/usr/bin/php$selected_version"
update-alternatives --set php-config "/usr/bin/php-config$selected_version"
update-alternatives --set phpize "/usr/bin/phpize$selected_version"

# disable all libapache2 php mods
for version in ${versions[@]}; do
	a2dismod "php$version"
done

# enable the selected version and restart apache
a2enmod "php$selected_version"
service apache2 restart

Thanks for this 👍