How can I install a recent version of php? - php

Question

I have a problem with a Symfony project that I have to work on, when I try a 'composer install' on my bash, I have this message :
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Your requirements could not be resolved to an installable set of packages.
Problem 1
- Installation request for ocramius/package-versions 1.5.1 -> satisfiable by ocramius/package-versions[1.5.1].
- ocramius/package-versions 1.5.1 requires php ^7.3.0 -> your PHP version (7.2.24) does not satisfy that requirement.
Problem 2
- ocramius/package-versions 1.5.1 requires php ^7.3.0 -> your PHP version (7.2.24) does not satisfy that requirement.
- ocramius/proxy-manager 2.2.3 requires ocramius/package-versions ^1.1.3 -> satisfiable by ocramius/package-versions[1.5.1].
- Installation request for ocramius/proxy-manager 2.2.3 -> satisfiable by ocramius/proxy-manager[2.2.3].
It seems obvious that my php version isn't up-to-date and I have to upgrade to the 7.3.0 version minimum, but when I make an 'apt search php', the latest version that I have is 7.2 and the 'php -v' command return this message :
PHP 7.2.24-0ubuntu0.18.04.3 (cli) (built: Feb 11 2020 15:55:52) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies
with Zend OPcache v7.2.24-0ubuntu0.18.04.3, Copyright (c) 1999-2018, by Zend Technologies
Did anyone how can I force the upgrade of my php version ? It will be very helpfull.
Thanks & have a great day

Answer 1

You can upgrade your PHP version, depending of your OS but you can also "fix" the PHP version in your project with composer.json. In your composer.json you may have a "config" key, add "platform" with your PHP version, 7.2 in your case:
{
"name": "xxxx",
...
"config": {
"platform": {
"php": "7.3"
}
},
...
}
It's recommended to fix the version that you have in production :
Official doc: https://getcomposer.org/doc/06-config.md#platform
Check also this blog article : https://blog.martinhujer.cz/17-tips-for-using-composer-efficiently/ (Tip #15)
To update PHP version to 7.3 on linux, here is steps :
sudo apt-get update
sudo apt -y install software-properties-common
sudo add-apt-repository ppa:ondrej/php
sudo apt-get update
sudo apt -y install php7.3
If you need to install additional packages:
sudo apt-get install -y php7.3-{bcmath,bz2,intl,gd,mbstring,mysql,zip}