<?php
 
// NOTE: array of sample input strings to demonstrate
$inputs = array(
	'my_fiancée',            // match expected
	'über',                  // match expected
	'my_bloody_valentine',   // match expected
	'"ABC, Easy as 123!"',   // match expected
	'whocares@whocares.com', // match NOT expected
	"'foo'",                 // match expected
	'bar?');                 // match NOT expected
 
foreach($inputs as $input) {
	if (!preg_match("/^[\pL0-9_.,!\"' ]+$/u", $input)) {
        //                                ^
		echo "\"$input\" => error\r\n"; // FORNOW: to explicitly note non-matches
		//echo 'error';
    } else { // FORNOW: else to explicitly indicate matches
    	echo "\"$input\" => all good\r\n";
    }
}
 
?>

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