<?php
error_reporting(-1);
ini_set('display_errors', true);

$savedValues = [];
$searchForVariableNames = ['$MetaKeys', '$MetaDesc'];

foreach(['test2.php', 'test3.php'] as $filename) {
    $srcText = file_get_contents($filename);
    $tokens = token_get_all($srcText);

    // use this to visualize tokens...
    /* foreach($tokens as $token) {
        if(is_array($token)) {
            echo token_name($token[0]) . "\t" . $token[1] . "\t" . $token[2] . "\n";
        } else {
            echo ' > ' . $token . "\n";
        }
    } */

    for($x = 0; $x < count($tokens); $x++) {
        $token = $tokens[$x];
        if(is_array($token)) {

            if($token[0] === T_VARIABLE && in_array($token[1], $searchForVariableNames, true)) {
                // look ahead
                $y = $x;

                // if you really want to make it pretty, add all the possible token types here with a separate "no-save" path,
                // instead of assuming it will always be followed by T_CONSTANT_ENCAPSED_STRING ... else, this code will error out on eg.
                // $MetaDesc = $anotherVar;
                while(isset($tokens[$y]) && $tokens[$y][0] !== T_CONSTANT_ENCAPSED_STRING) {
                    $y++;

                    // reasonable limit
                    if($y - $x >= 5) {
                        throw new \Exception("Can't find value for token: {$token[1]} within a reasonable amount of tokens (started on line {$token[2]})");
                    }
                };

                if(!isset($tokens[$y])) {
                    throw new \Exception("Reached the end of file with no string for token: " . $token[1] . " (started on line " . $token[2] . ").  Probably set to a not-a-string.");
                }

                // now we have the variable-name token in $x and the value in $y
                // (probably)

                $savedValues[$filename] = $savedValues[$filename] ?? [];
                $savedValues[$filename][] = [
                    $tokens[$x][1] => $tokens[$y][1]
                ];

            }
        }

    }
}

var_dump($savedValues);