Reuben Siama - Switch PHP Versions

I found myself in a situation where I needed to switch my PHP veresion from 8.3 to 8.0 on Ubuntu. After doing some research, I found the terminal commands to switch PHP versions. Initially, I faced a few challenges, but after some trial and error, I successfully mad the switch. I'd like to share the steps with you.

Step 1: Check Installed PHP Versions

First, let's check which versions of PHP are installed on the system.

Open your terminal by pressing ctrl + alt + t

user@my-pc:~$ cd /etc/php
user@my-pc:/etc/php$ ls
8.0 8.3

In the above commands, we can see that php versions 8.0 and 8.3 installed on my system.

Step 2: Check Current PHP Version

Now, let's check which version of PHP is currently in use.

user@my-pc:~$ php -v
PHP 8.3.13 (cli) (built: Oct 30 2024 11:28:41) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.3.13, Copyright (c) Zend Technologies
    with Zend OPcache v8.3.13, Copyright (c), by Zend Technologies

From the output, we can see that I'm currently using PHP 8.3

Setp 3: Switch PHP Versions

To switch from PHP 8.3 to PHP 8.0, we will first change the PHP version for the CLI by running the following command:

user@my-pc:~$ sudo update-alternatives --set php /usr/bin/php8.0

Next, disable PHP 8.3, enable PHP 8.0 and then restart Apache:

user@my-pc:~$ sudo a2dismod php8.3
user@my-pc:~$ sudo a2enmod php8.0
user@my-pc:~$ sudo systemctl restart apache2

Step 4: Verify PHP Version Change

Now, let's verify the switch was successful:

user@my-pc:~$ php -v
PHP 8.0.30 (cli) (built: Sep 27 2024 04:11:42) ( NTS )
Copyright (c) The PHP Group
Zend Engine v4.0.30, Copyright (c) Zend Technologies
    with Zend OPcache v8.0.30, Copyright (c), by Zend Technologies

As you can see, the PHP version has successfully switched to 8.0

Optional: Create an Alias for Easier Switching

If you need to switch PHP versions frequently, you may want to create an alias to make this process faster. Here's how you can do that.

1. Open `.bashrc` File

To make the switch even easier, we can add a custom function to our .bashrc file. This function will allow you to switch PHP versions in one command.

Open your terminal any type:

user@my-pc:~$ nano ~/.bashrc

Scroll to the end of the file and add the following function:

switchphp(){
        sudo a2dismod php"$1"
        sudo a2enmod php"$2"
        sudo systemctl restart apache2
        sudo update-alternatives --set php /usr/bin/php"$2"
}

In this function, $1 and $2 are the PHP versions you want to switch between.

Save and Reload `.bashrc`

After saving the file, reload .bashrc file by running

user@my-pc:~$ source ~/.bashrc

3. Use the Alias

Now, we can use the switchphp function to easily switch between PHP versions. For example, to switch from PHP 8.0 to 8.3, you can simply run:

user@my-pc:~$ switchphp 8.0 8.3

This will switch PHP from version 8.0 to 8.3 in a single command.

Switch PHP Versions