change-php-version.sh

#!/bin/bash

# License: Eclipse Public License - v 2.0 (https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.html)
# Updated on November 7, 2022

if [[ $EUID -ne 0 ]]; then
  echo -e "\nThis script must be run as root. Exiting. . . .\n\n"
  exit 1
fi

if [ -z "$1" ]; then
  echo -e "\nOne must pass the PHP version to enable. Exiting. . . .\n\n"
  exit 1
fi

if ! [[ "$1" =~ ^[0-9]+\.[0-9]+$ ]]; then
  echo -e "\nOne must pass a valid number like 7.3 or 7.4. Exiting. . . .\n\n"
  exit 1
fi

lcVersion="$1"

# Grab the first character and convert to an integer.
# By the way, bash works well with integers, not floats.
# And we just need to know if PHP 8 or above.
lnPHPVersion="$((${lcVersion:0:1} + 0))"

# Ensure that the PHP version is installed.
echo -e "==============================================="
echo -e "Installing (if not already installed) basic needed libraries. . . .\n"

apt install "php${lcVersion}"
apt install "php${lcVersion}-bcmath"
apt install "php${lcVersion}-cli"
apt install "php${lcVersion}-common"
apt install "php${lcVersion}-curl"
apt install "php${lcVersion}-gd"

if [ "${lnPHPVersion}" -lt 8 ]; then
  apt install "php${lcVersion}-json"
else
  # From https://github.com/manala/ansible-roles/issues/548
  echo -e "\njson extension is now embedded in php starting with version 8.\n"
fi

apt install "php${lcVersion}-mbstring"
apt install "php${lcVersion}-mysql"
apt install "php${lcVersion}-opcache"
apt install "php${lcVersion}-readline"
apt install "php${lcVersion}-xml"
apt install "php${lcVersion}-zip"

systemctl restart apache2

apt list "php${lcVersion}*" --installed

echo -e "==============================================="
echo -e "Validating the existence of PHP v ${lcVersion}\n"

if [ ! -d "/etc/php/${lcVersion}" ]; then
  echo -e "\nPHP v ${lcVersion} is not installed. Exiting. . . .\n"
  exit 1
fi

lcPHPIniFile="/etc/php/${lcVersion}/apache2/php.ini"

if [ ! -f ${lcPHPIniFile} ]; then
  echo -e "\nPHP v ${lcVersion} ini file (${lcPHPIniFile}) is missing. Exiting. . . .\n"
  exit 1
fi

echo -e "==============================================="
echo -e "Disabling all PHP versions. . . .\n"

for lcDir in /etc/php/*; do
  lcPHPVer=$(basename "$lcDir")
  echo -e "Running a2dismod php$lcPHPVer\n"
  a2dismod "php$lcPHPVer"
done

echo -e "==============================================="
echo -e "Disabling mpm_prefork, mpm_worker, mpm_event. . . .\n"
echo -e "Enabling PHP will re-enable the appropriate modules above. . . .\n"

a2dismod mpm_prefork
a2dismod mpm_worker
a2dismod mpm_event

echo -e "\nRestarting apache\n"
systemctl restart apache2

echo -e "==============================================="
echo -e "Enabling php${lcVersion}. . . .\n"

a2enmod "php${lcVersion}"

systemctl restart apache2

echo -e "==============================================="
echo -e "Running update-alternatives. . . .\n"

update-alternatives --set php "/usr/bin/php${lcVersion}"
update-alternatives --set phar "/usr/bin/phar${lcVersion}"
update-alternatives --set phar.phar "/usr/bin/phar.phar${lcVersion}"
update-alternatives --set phpize "/usr/bin/phpize${lcVersion}"
update-alternatives --set php-config "/usr/bin/php-config${lcVersion}"

echo -e "==============================================="
echo -e "Restarting apache\n"

systemctl restart apache2

echo -e "==============================================="
echo -e "Displaying PHP version info with ${lcPHPIniFile}. . . .\n\n"

php -v

echo -e "\n"

php -c "${lcPHPIniFile}" -i | grep 'memory_limit'
php -c "${lcPHPIniFile}" -i | grep 'max_input_vars'

echo -e "\n"
echo -e "==============================================="