List all the functions in current directory

regex_list_functions.php

<?php 

$functions = [];

foreach( glob("./{,*/,*/*/,*/*/*/}*.php" , GLOB_BRACE ) as $file ) {
    
    $matches = [];
    $content = file_get_contents( $file );

    preg_match_all( "/function\s(.*)\(/", $content, $matches );
    $functions = array_merge( $matches[1] , $functions );
}

print_r( $functions );