test.php

<?php

// Example usage: php check.php "Please speel check thsi sentence"
// Example output: Please <speel> check <thsi> sentence

$dictionary = file('/usr/share/dict/words', FILE_IGNORE_NEW_LINES);
$words = explode(" ", trim($argv[1]));

foreach ($words as $word) {
        $found = false;
        foreach ($dictionary as $dictword) {
                if ($dictword == $word) {
                        $found = true;
                        break;
                }
        }
        if ($found) {
                echo $word;
        } else {
                echo "<" . $word . ">";
        }
        echo " ";
}