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  2. <html>
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  3.  <head>
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  4.   <meta http-equiv="content-type" content="text/html; charset=UTF-8">
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  5.   <title>测试文件指针是否到了文件结束的位置</title>
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  6. 

  7.  </head>
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  8.  <body><div class="manualnavbar" style="text-align: center;">
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  9.  <div class="prev" style="text-align: left; float: left;"><a href="function.fclose.html">fclose</a></div>
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  11.  <div class="up"><a href="ref.filesystem.html">Filesystem 函数</a></div>
    12. 

  12.  <div class="home"><a href="index.html">PHP Manual</a></div>
    13. 

  13. </div><hr /><div id="function.feof" class="refentry">
    14. 

  14.  <div class="refnamediv">
    15. 

  15.   <h1 class="refname">feof</h1>
    16. 

  16.   <p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">feof</span> &mdash; <span class="dc-title">测试文件指针是否到了文件结束的位置</span></p>
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  17. 

  18.  </div>
    19. 

  19.  <div class="refsect1 description" id="refsect1-function.feof-description">
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  20.   <h3 class="title">说明</h3>
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  21.   <div class="methodsynopsis dc-description">
    22. 

  22.    <span class="type">bool</span> <span class="methodname"><strong>feof</strong></span>
    23. 

  23.     ( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$handle</code></span>
    24. 

  24.    )</div>
    25. 

  25. 

  26.   <p class="para rdfs-comment">
    27. 

  27.    测试文件指针是否到了文件结束的位。
    28. 

  28.   </p>
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  29.  </div>
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  30. 

  31.  
    32. 

  32.  <div class="refsect1 parameters" id="refsect1-function.feof-parameters">
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  33.   <h3 class="title">参数</h3>
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  34.   <p class="para">
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  35.    <dl>
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  36. 

  37.     <dt>
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  38. 

  39.      <span class="term"><em><code class="parameter">handle</code></em></span>
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  40.      <dd>
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  41. 

  42.       <p class="para">文件指针必须是有效的，必须指向由
    43. 

  43.  <span class="function"><a href="function.fopen.html" class="function">fopen()</a></span> 或  <span class="function"><a href="function.fsockopen.html" class="function">fsockopen()</a></span> 成功打开的文件(并还未由  <span class="function"><a href="function.fclose.html" class="function">fclose()</a></span> 关闭)。</p>
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  44.      </dd>
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  45. 

  46.     </dt>
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  47. 

  48.    </dl>
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  49. 

  50.   </p>
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  51.  </div>
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  52. 

  53.  
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  54.  <div class="refsect1 returnvalues" id="refsect1-function.feof-returnvalues">
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  55.   <h3 class="title">返回值</h3>
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  56.   <p class="para">
    57. 

  57.    如果文件指针到了 EOF 或者出错时则返回 <strong><code>TRUE</code></strong>，否则返回一个错误（包括 socket
    58. 

  58.    超时），其它情况则返回 <strong><code>FALSE</code></strong>。
    59. 

  59.   </p>
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  60.  </div>
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  61. 

  62.  
    63. 

  63.  <div class="refsect1 notes" id="refsect1-function.feof-notes">
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  64.   <h3 class="title">注释</h3>
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  65.   <div class="warning"><strong class="warning">Warning</strong>
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  66.    <p class="para">
    67. 

  67.         如果服务器没有关闭由  <span class="function"><a href="function.fsockopen.html" class="function">fsockopen()</a></span> 所打开的连接， <span class="function"><strong>feof()</strong></span>
    68. 

  68.     会一直等待直到超时。要解决这个问题可参见以下范例：
    69. 

  69.     <div class="example" id="example-2240">
    70. 

  70.      <p><strong>Example #1 处理  <span class="function"><strong>feof()</strong></span> 的超时</strong></p>
    71. 

  71.      <div class="example-contents">
    72. 

  72. <div class="phpcode"><code><span style="color: #000000">
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  73. <span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">function&nbsp;</span><span style="color: #0000BB">safe_feof</span><span style="color: #007700">(</span><span style="color: #0000BB">$fp</span><span style="color: #007700">,&nbsp;&amp;</span><span style="color: #0000BB">$start&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">NULL</span><span style="color: #007700">)&nbsp;{<br />&nbsp;</span><span style="color: #0000BB">$start&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">microtime</span><span style="color: #007700">(</span><span style="color: #0000BB">true</span><span style="color: #007700">);<br /><br />&nbsp;return&nbsp;</span><span style="color: #0000BB">feof</span><span style="color: #007700">(</span><span style="color: #0000BB">$fp</span><span style="color: #007700">);<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;$fp&nbsp;的赋值是由之前&nbsp;fsockopen()&nbsp;打开&nbsp;&nbsp;*/<br /><br /></span><span style="color: #0000BB">$start&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">NULL</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$timeout&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">ini_get</span><span style="color: #007700">(</span><span style="color: #DD0000">'default_socket_timeout'</span><span style="color: #007700">);<br /><br />while(!</span><span style="color: #0000BB">safe_feof</span><span style="color: #007700">(</span><span style="color: #0000BB">$fp</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$start</span><span style="color: #007700">)&nbsp;&amp;&amp;&nbsp;(</span><span style="color: #0000BB">microtime</span><span style="color: #007700">(</span><span style="color: #0000BB">true</span><span style="color: #007700">)&nbsp;-&nbsp;</span><span style="color: #0000BB">$start</span><span style="color: #007700">)&nbsp;&lt;&nbsp;</span><span style="color: #0000BB">$timeout</span><span style="color: #007700">)<br />{<br />&nbsp;</span><span style="color: #FF8000">/*&nbsp;Handle&nbsp;*/<br /></span><span style="color: #007700">}<br /></span><span style="color: #0000BB">?&gt;</span>
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  74. </span>
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  75. </code></div>
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  76.      </div>
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  77. 

  78.     </div>
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  79.    </p>
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  80.   </div>
    81. 

  81.   <div class="warning"><strong class="warning">Warning</strong>
    82. 

  82.    <p class="para">
    83. 

  83.     如果传递的文件指针无效可能会陷入无限循环中，因为  <span class="function"><strong>feof()</strong></span> 不会返回 <strong><code>TRUE</code></strong>。
    84. 

  84.     <div class="example" id="example-2241">
    85. 

  85.      <p><strong>Example #2 使用无效文件指针的  <span class="function"><strong>feof()</strong></span> 例子 </strong></p>
    86. 

  86.      <div class="example-contents">
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  87. <div class="phpcode"><code><span style="color: #000000">
    88. 

  88. <span style="color: #0000BB">&lt;?php<br /></span><span style="color: #FF8000">//&nbsp;如果文件不可读取或者不存在，fopen&nbsp;函数返回&nbsp;FALSE<br /></span><span style="color: #0000BB">$file&nbsp;</span><span style="color: #007700">=&nbsp;@</span><span style="color: #0000BB">fopen</span><span style="color: #007700">(</span><span style="color: #DD0000">"no_such_file"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"r"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">//&nbsp;来自&nbsp;fopen&nbsp;的&nbsp;FALSE&nbsp;会发出一条警告信息并在这里陷入无限循环<br /></span><span style="color: #007700">while&nbsp;(!</span><span style="color: #0000BB">feof</span><span style="color: #007700">(</span><span style="color: #0000BB">$file</span><span style="color: #007700">))&nbsp;{<br />}<br /><br /></span><span style="color: #0000BB">fclose</span><span style="color: #007700">(</span><span style="color: #0000BB">$file</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?&gt;</span>
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  89. </span>
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  90. </code></div>
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  91.      </div>
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