mirror of
https://github.com/fofolee/uTools-Manuals.git
synced 2025-06-18 05:26:57 +08:00
155 lines
6.3 KiB
HTML
155 lines
6.3 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
||
<html>
|
||
<head>
|
||
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
|
||
<title>将文件截断到给定的长度</title>
|
||
</head>
|
||
<body class="docs"><div id="layout">
|
||
<div id="layout-content"><div id="function.ftruncate" class="refentry">
|
||
<div class="refnamediv">
|
||
<h1 class="refname">ftruncate</h1>
|
||
<p class="verinfo">(PHP 4, PHP 5, PHP 7)</p><p class="refpurpose"><span class="refname">ftruncate</span> — <span class="dc-title">将文件截断到给定的长度</span></p>
|
||
|
||
</div>
|
||
|
||
<div class="refsect1 description" id="refsect1-function.ftruncate-description">
|
||
<h3 class="title">说明</h3>
|
||
<div class="methodsynopsis dc-description">
|
||
<span class="methodname"><strong>ftruncate</strong></span>
|
||
( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$handle</code></span>
|
||
, <span class="methodparam"><span class="type">int</span> <code class="parameter">$size</code></span>
|
||
) : <span class="type">bool</span></div>
|
||
|
||
<p class="para rdfs-comment">
|
||
接受文件指针 <code class="parameter">handle</code> 作为参数，并将文件大小截取为
|
||
<code class="parameter">size</code>。
|
||
</p>
|
||
</div>
|
||
|
||
|
||
<div class="refsect1 parameters" id="refsect1-function.ftruncate-parameters">
|
||
<h3 class="title">参数</h3>
|
||
<p class="para">
|
||
<dl>
|
||
|
||
|
||
<dt>
|
||
<code class="parameter">handle</code></dt>
|
||
|
||
<dd>
|
||
|
||
<p class="para">
|
||
文件指针。
|
||
</p>
|
||
<blockquote class="note"><p><strong class="note">Note</strong>:
|
||
<p class="para">
|
||
The <code class="parameter">handle</code> must be open for writing.
|
||
</p>
|
||
</p></blockquote>
|
||
</dd>
|
||
|
||
|
||
|
||
<dt>
|
||
<code class="parameter">size</code></dt>
|
||
|
||
<dd>
|
||
|
||
<p class="para">
|
||
The size to truncate to.
|
||
</p>
|
||
<blockquote class="note"><p><strong class="note">Note</strong>:
|
||
<p class="para">
|
||
If <code class="parameter">size</code> is larger than the file then the file
|
||
is extended with null bytes.
|
||
</p>
|
||
<p class="para">
|
||
If <code class="parameter">size</code> is smaller than the file then the file
|
||
is truncated to that size.
|
||
</p>
|
||
</p></blockquote>
|
||
</dd>
|
||
|
||
|
||
</dl>
|
||
|
||
</p>
|
||
</div>
|
||
|
||
|
||
<div class="refsect1 returnvalues" id="refsect1-function.ftruncate-returnvalues">
|
||
<h3 class="title">返回值</h3>
|
||
<p class="para">
|
||
成功时返回 <strong><code>TRUE</code></strong>， 或者在失败时返回 <strong><code>FALSE</code></strong>。
|
||
</p>
|
||
</div>
|
||
|
||
|
||
<div class="refsect1 changelog" id="refsect1-function.ftruncate-changelog">
|
||
<h3 class="title">更新日志</h3>
|
||
<p class="para">
|
||
<table class="doctable informaltable">
|
||
|
||
<thead>
|
||
<tr>
|
||
<th>版本</th>
|
||
<th>说明</th>
|
||
</tr>
|
||
|
||
</thead>
|
||
|
||
<tbody class="tbody">
|
||
<tr>
|
||
<td>4.3.3</td>
|
||
<td>
|
||
在 PHP 4.3.3 之前，<span class="function"><strong>ftruncate()</strong></span> 在成功时返回一个
|
||
<span class="type"><a href="language.types.integer.html" class="type integer">integer</a></span> 值 1，而不是 <span class="type"><a href="language.types.boolean.html" class="type boolean">boolean</a></span> 的 <strong><code>TRUE</code></strong>。
|
||
</td>
|
||
</tr>
|
||
|
||
</tbody>
|
||
|
||
</table>
|
||
|
||
</p>
|
||
</div>
|
||
|
||
|
||
<div class="refsect1 examples" id="refsect1-function.ftruncate-examples">
|
||
<h3 class="title">范例</h3>
|
||
<p class="para">
|
||
<div class="example" id="example-2809">
|
||
<p><strong>Example #1 File truncation example</strong></p>
|
||
<div class="example-contents">
|
||
<div class="phpcode"><pre><span style="color: #000000">
|
||
<span style="color: #0000BB"><?php<br />$filename </span><span style="color: #007700">= </span><span style="color: #DD0000">'lorem_ipsum.txt'</span><span style="color: #007700">;<br /><br /></span><span style="color: #0000BB">$handle </span><span style="color: #007700">= </span><span style="color: #0000BB">fopen</span><span style="color: #007700">(</span><span style="color: #0000BB">$filename</span><span style="color: #007700">, </span><span style="color: #DD0000">'r+'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">ftruncate</span><span style="color: #007700">(</span><span style="color: #0000BB">$handle</span><span style="color: #007700">, </span><span style="color: #0000BB">rand</span><span style="color: #007700">(</span><span style="color: #0000BB">1</span><span style="color: #007700">, </span><span style="color: #0000BB">filesize</span><span style="color: #007700">(</span><span style="color: #0000BB">$filename</span><span style="color: #007700">)));<br /></span><span style="color: #0000BB">rewind</span><span style="color: #007700">(</span><span style="color: #0000BB">$handle</span><span style="color: #007700">);<br />echo </span><span style="color: #0000BB">fread</span><span style="color: #007700">(</span><span style="color: #0000BB">$handle</span><span style="color: #007700">, </span><span style="color: #0000BB">filesize</span><span style="color: #007700">(</span><span style="color: #0000BB">$filename</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">fclose</span><span style="color: #007700">(</span><span style="color: #0000BB">$handle</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span>
|
||
</span>
|
||
</pre></div>
|
||
</div>
|
||
|
||
</div>
|
||
</p>
|
||
</div>
|
||
|
||
|
||
<div class="refsect1 notes" id="refsect1-function.ftruncate-notes">
|
||
<h3 class="title">注释</h3>
|
||
<blockquote class="note"><p><strong class="note">Note</strong>:
|
||
<p class="para">
|
||
The file pointer is <em class="emphasis">not</em> changed.
|
||
</p>
|
||
</p></blockquote>
|
||
</div>
|
||
|
||
|
||
<div class="refsect1 seealso" id="refsect1-function.ftruncate-seealso">
|
||
<h3 class="title">参见</h3>
|
||
<p class="para">
|
||
<ul class="simplelist">
|
||
<li class="member"><span class="function"><a href="fopen.html" class="function" rel="rdfs-seeAlso">fopen()</a> - 打开文件或者 URL</span></li>
|
||
<li class="member"><span class="function"><a href="fseek.html" class="function" rel="rdfs-seeAlso">fseek()</a> - 在文件指针中定位</span></li>
|
||
</ul>
|
||
</p>
|
||
</div>
|
||
|
||
</div></div></div></body></html> |