fseek
在文件指针中定位
<span class="token php language-php"><span class="token delimiter important"><?php</span> <span class="token variable">$file</span> <span class="token operator">=</span> <span class="token function">fopen</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"test.txt"</span><span class="token punctuation">,</span><span class="token string double-quoted-string">"r"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// 读取第一行</span> <span class="token function">fgets</span><span class="token punctuation">(</span><span class="token variable">$file</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// 倒回文件的开头</span> <span class="token function">fseek</span><span class="token punctuation">(</span><span class="token variable">$file</span><span class="token punctuation">,</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token delimiter important">?></span></span>