filesize

例

<span class="token php language-php"><span class="token delimiter important"><？php</span>
<span class="token keyword">echo</span> <span class="token function">filesize</span> <span class="token punctuation">（</span> <span class="token string double-quoted-string">"test.txt"</span> <span class="token punctuation">）</span> <span class="token punctuation">;</span>
<span class="token delimiter important">？></span></span>

出力：

 20