Here 2 equivalent commands

[root@apache1 dokuwiki]# cat php_version.php
<? php phpinfo(); ?>
[root@apache1 dokuwiki]# php php_version.php

Here we can see php version and detail config like php.ini file, version of each module…

[root@apache1 dokuwiki]# php -i
phpinfo()
PHP Version => 5.6.25

System => Linux apache1 3.10.0-xxx.42.2.el7.x86_64 #1 SMP Tue Aug 31 20:15:00 UTC 2021 x86_64
Build Date => Sep  6 2016 08:19:38
Server API => Command Line Interface
Virtual Directory Support => disabled
Configuration File (php.ini) Path => /etc/opt/rh/rh-php56
Loaded Configuration File => /etc/opt/rh/rh-php56/php.ini
Scan this dir for additional .ini files => /etc/opt/rh/rh-php56/php.d
Additional .ini files parsed => /etc/opt/rh/rh-php56/php.d/20-bz2.ini,
/etc/opt/rh/rh-php56/php.d/20-calendar.ini,
/etc/opt/rh/rh-php56/php.d/20-ctype.ini,
...

List loaded modules

[root@apache1 dokuwiki]# php -m
[PHP Modules]
bz2
calendar
Core
ctype
curl
date
dom
ereg
exif
fileinfo
filter
ftp
gettext
hash
iconv
json
ldap
libxml
mbstring
mhash
openssl
pcntl
pcre
Phar
readline
Reflection
session
SimpleXML
sockets
...