这样就算会了PHP么？-10

关于基本的文件读写内容：

<?php
    echo "readfile function:<br>";
    readfile("tm.txt");
    echo "<br>";
    echo "file function:<br>";
    $f_arr = file("tm.txt");
    foreach ($f_arr as $cont) {
        echo $cont."<br>";
    }
    echo "file_get_contents function:<br>";
    $f_chr = file_get_contents(‘tm.txt‘);
    echo $f_chr;

?>