Simplified version of rhukster/sphp.sh focusing only on PHP switch

sphp.sh

#!/bin/bash

# Original version: https://raw.githubusercontent.com/rhukster/sphp.sh/main/sphp.sh

script_version=1.0.0

# Supported PHP versions
brew_array=("5.6" "7.0" "7.1" "7.2" "7.3" "7.4" "8.0" "8.1" "8.2" "8.3" "8.4")
target_version=$1
php_version="php@$target_version"

# Display help and exit if the user did not specify a version
if [[ -z "$target_version" ]]; then
    echo "PHP Switcher - v$script_version"
    echo
    echo "Switch between Brew-installed PHP versions."
    echo
    echo "usage: $(basename "$0") version [-s|-s=*] [-c=*]"
    echo
    echo "    version    one of:" "${brew_array[@]}"
    echo
    exit
fi

homebrew_path=$(brew --prefix)

# From the list of supported PHP versions, build array of PHP versions actually
# installed on the system via brew
for version in ${brew_array[*]}; do
    if [[ -d "$homebrew_path/etc/php/$version" ]]; then
        php_installed_array+=("$version")
    fi
done

# Check that the requested version is supported
if [[ " ${brew_array[*]} " == *"$target_version"* ]]; then
    # Check that the requested version is installed
    if [[ " ${php_installed_array[*]} " == *"$target_version"* ]]; then
        # Switch Shell
        echo "Switching to $php_version"
        echo "Switching your shell"
        for i in "${php_installed_array[@]}"; do
            brew unlink "php@$i"
        done
        brew link --force "$php_version"

        echo
        php -v
        echo

        echo "All done!"
    else
        echo "Sorry, but $php_version is not installed via brew. Install by running: brew install $php_version"
    fi
else
    echo "Unknown version of PHP. PHP Switcher can only handle arguments of:" "${brew_array[@]}"
fi