<?php
$text = '[this is block
this is also same "block"
this is same block
another same block]
new block!
another new block!
[this is new block
this is also a new block]';
var_export(preg_split('~\[[^\]]*](*SKIP)(*FAIL)|\R~', $text));
array (
0 => '[this is block
this is also same "block"
this is same block
another same block]',
1 => 'new block!',
2 => 'another new block!',
3 => '[this is new block
this is also a new block]',
)
Output for 8.3.5
Warning: PHP Startup: Unable to load dynamic library 'sodium.so' (tried: /usr/lib/php/8.3.5/modules/sodium.so (libsodium.so.23: cannot open shared object file: No such file or directory), /usr/lib/php/8.3.5/modules/sodium.so.so (/usr/lib/php/8.3.5/modules/sodium.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0
array (
0 => '[this is block
this is also same "block"
this is same block
another same block]',
1 => 'new block!',
2 => 'another new block!',
3 => '[this is new block
this is also a new block]',
)