PHP Version Switcher (Bash Shell Script)

php_version_switcher.sh

#!/bin/bash
#================================================================
# HEADER
#================================================================
#% SYNOPSIS
#+    ${SCRIPT_NAME} args ...
#%
#% DESCRIPTION
#%    A simple script to switch the current PHP version being used.
#%    used. The switch is reflected system-wide, including in the
#%    terminal, and any Apache/NGINX web server configurations
#%    (which may or may not be running).
#%
#% OPTIONS
#%    -h, --help                    Print this help
#%    -v, --version                 Print script information
#%
#% EXAMPLES
#%    ${SCRIPT_NAME}
#%    ${SCRIPT_NAME} 7.4
#%
#================================================================
#- IMPLEMENTATION
#-    version         ${SCRIPT_NAME} (nicholas-morgan.com) v1.0.0
#-    author          Nick Morgan
#-    copyright       Copyright (c) http://nicholas-morgan.com
#-    date            January 22, 2021
#-    license         GNU General Public License
#-    script_id       0
#-
#================================================================
#  HISTORY
#     2021/01/22 : v1.0.0 : Script creation and published
#
#================================================================
# END_OF_HEADER
#================================================================

# Some colors to help make the script stand out a bit!
NOCOLOR='\033[0m'
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'

echo -e "${YELLOW}";
echo "--------------------";
echo "PHP Version Switcher";
echo "--------------------";
echo -e "${NOCOLOR}";

# In case the PHP version has already been changed in the current bash session, reload the bash profile first to ensure the current PHP version is correct within this script.
source ~/.bash_profile

echo -e "The current PHP version running is ${GREEN}$PHP_VERSION${NOCOLOR}.";
echo "";

# Determine what PHP version should be switched to. This is done by examining what the first input argument of the script is, or if no argument was passed, asking the user what it should be.
if [[ "$1" != "" ]]; then
    NEW_PHP_VERSION="$1"
else
    echo -e "What PHP version should be switched to? ${YELLOW}[7.4, 7.3, 7.2]${NOCOLOR}";
	read NEW_PHP_VERSION;
	echo "";
fi

echo -e "You have specified to switch the PHP version to ${YELLOW}$NEW_PHP_VERSION${NOCOLOR}.";
echo "";

# Some error checking to ensure it's not being changed to the current version
if [ $NEW_PHP_VERSION = $PHP_VERSION ]; then
	echo -e "${RED}Can not switch PHP version to $NEW_PHP_VERSION, because that is already the current PHP version!${NOCOLOR}";
	exit 1;
fi

# Execute the PHP version change...
if [ $NEW_PHP_VERSION = "7.4" ] || [ $NEW_PHP_VERSION = "7.3" ] || [ $NEW_PHP_VERSION = "7.2" ]; then

	echo -e "${YELLOW}Switching PHP version to $NEW_PHP_VERSION...${NOCOLOR}";
	echo "";


	# Ensure all possible php services with brew are stopped before starting the service for the new version
	sudo echo "Stopping all possible currently running php services for all possible PHP versions...";
	sudo brew services stop php@7.2;
	sudo brew services stop php@7.3;
	sudo brew services stop php@7.4;
	echo "Done!";
	echo "";

	# Start the service for the correct PHP version being changed to
	echo "Starting the service for the new PHP version $NEW_PHP_VERSION...";
	if [ $NEW_PHP_VERSION = "7.4" ]; then
		sudo brew services start php@7.4;
	fi
	if [ $NEW_PHP_VERSION = "7.3" ]; then
		sudo brew services start php@7.3;
	fi
	if [ $NEW_PHP_VERSION = "7.2" ]; then
		sudo brew services start php@7.2;
	fi
	echo "Done!";
	echo "";

	
	#export PHP_VERSION=7.4


	# Store the new PHP version in the file which sets the PHP version variable in the .bash_profile. A separate file is used for this.
	> ~/.bash_php_version
	echo "export PHP_VERSION=$NEW_PHP_VERSION" > ~/.bash_php_version

	# Reload the bash_profile so that the new PHP_VERSION environment variable will be reflected (without having to open a new bash session)
	#source ~/.bash_profile

	echo -e "${GREEN}The PHP version has been switched to $NEW_PHP_VERSION!${NOCOLOR}";
	echo -e "${YELLOW}Warning:${NOCOLOR} The new PHP version may not be reflected in the current bash session. So, open a new one, or manually run 'source ~/.bash_profile' to reflect the updated version in the current bash session.";
	echo "";

	# Reflect the updated PHP version in the current bash session.
	#set PHP_VERSION="$NEW_PHP_VERSION";
	#source ~/.bash_profile # Not working for some reason, but works if you run it manually after the script is done?
else
	echo -e "${RED}The PHP version $NEW_PHP_VERSION you entered was not recognized, so no changes were made!${NOCOLOR}";
	exit 2;
fi

exit 0; # successfully executed!