Why phpinfo() shows a different version than php -v?

I install php via brew. With brew install PHP. My version of php-cli is 7.2

• But, if I use phpinfo() on my server, I get php version 7.1.
• If I use php -v in my terminal, I get php version 7.2.

Disclaimer: I'm adding this hopefully extensive answer as part of the Revival badge. (Answer more than 30 days after a question was asked as first answer scoring 2 or more)

TL;DR

php -v settings can be different from phpinfo() inside your web-server due to the running service state of fpm and your webserver. Perhaps you need to restart php-fpm and/or your web-server (apache, nginx, ..).

Long version: Command line

Command-line based calls like php -v or php -i or php test.php will read your configuration, options and arguments every time you execute your script within a terminal.

This means if you update php in your operating system then you'll get the most recent version in your terminal session.

Attention: Depending on your PATH variables you still might get an older version.

What does this mean? Even if you update your php version on your operating system you might still have an older terminal session which links to an older php-binary.

Here is an example: I am an OSX user and installed php through brew. Currently php links to php@7.3. Here is my way to validate which versions are running where. For this I'm using which php.

$ which php
/usr/local/opt/php@7.3/bin/php

$ php -v
PHP 7.3.11 (cli) (built: Oct 24 2019 11:29:42) ( NTS )

// or the equivalent "absolute path" example

$ /usr/local/opt/php@7.3/bin/php -v
PHP 7.3.11 (cli) (built: Oct 24 2019 11:29:42) ( NTS )

I have multiple php-versions installed on my local system. I can run them all individually. Here is an example:

$ /usr/local/opt/php@7.2/bin/php -v
PHP 7.2.20 (cli) (built: Jul  5 2019 12:56:54) ( NTS )

Long version: Why is my phpinfo() using the wrong php version?

Since we now have an understanding that we can run multiple and different versions of php on a single operating system, lets dig into our web-server based script which runs phpinfo().

After installing a new php-version you'll have your binaries replaced by new versions. Awesome! but.. how does my running web server get notified about it?

For this I'll refer to the php documentation Apache 2.x on Unix systems Point 7. Also apache allows us to load different modules for PHP.

> Edit your httpd.conf to load the PHP module. [...]
>
> For PHP 7:
> LoadModule php7_module modules/libphp7.so
>
> For PHP 5:
> LoadModule php5_module modules/libphp5.so

Since you are upgrading from PHP 7.1 to PHP 7.2 there is probably no change but your webserver is still running the old linked version of php.

In this case a restart of your apache webserver should help so it can pickup the new binaries correctly.

Please let me know if this will help you to solve your issue. For all the other readers: If you think there is something missing OR there is something wrong in my explanation then please let me know with a comment.