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  1. <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    2. 

  2. <html>
    3. 

  3.  <head>
    4. 

  4.   <meta http-equiv="content-type" content="text/html; charset=UTF-8">
    5. 

  5.   <title>从文件指针中读取一行</title>
    6. 

  6. 

  7.  </head>
    8. 

  8.  <body><div class="manualnavbar" style="text-align: center;">
    9. 

  9.  <div class="prev" style="text-align: left; float: left;"><a href="function.fgetcsv.html">fgetcsv</a></div>
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  10.  <div class="next" style="text-align: right; float: right;"><a href="function.fgetss.html">fgetss</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.fgets" class="refentry">
    14. 

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

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

  16.   <p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">fgets</span> &mdash; <span class="dc-title">从文件指针中读取一行</span></p>
    17. 

  17. 

  18.  </div>
    19. 

  19.  <div class="refsect1 description" id="refsect1-function.fgets-description">
    20. 

  20.   <h3 class="title">说明</h3>
    21. 

  21.   <div class="methodsynopsis dc-description">
    22. 

  22.    <span class="type">string</span> <span class="methodname"><strong>fgets</strong></span>
    23. 

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

  24.    [, <span class="methodparam"><span class="type">int</span> <code class="parameter">$length</code></span>
    25. 

  25.   ] )</div>
    26. 

  26. 

  27.   <p class="para rdfs-comment">
    28. 

  28.    从文件指针中读取一行。
    29. 

  29.   </p>
    30. 

  30.  </div>
    31. 

  31. 

  32. 

  33.  <div class="refsect1 parameters" id="refsect1-function.fgets-parameters">
    34. 

  34.   <h3 class="title">参数</h3>
    35. 

  35.   <p class="para">
    36. 

  36.    <dl>
    37. 

  37. 

  38.     <dt>
    39. 

  39. 

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

  41.      <dd>
    42. 

  42. 

  43.       <p class="para">文件指针必须是有效的，必须指向由
    44. 

  44.  <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>
    45. 

  45.      </dd>
    46. 

  46. 

  47.     </dt>
    48. 

  48. 

  49.     <dt>
    50. 

  50. 

  51.      <span class="term"><em><code class="parameter">length</code></em></span>
    52. 

  52.      <dd>
    53. 

  53. 

  54.       <p class="para">
    55. 

  55.        从 <em><code class="parameter">handle</code></em>
    56. 

  56.    指向的文件中读取一行并返回长度最多为 <em><code class="parameter">length</code></em> - 1
    57. 

  57.    字节的字符串。碰到换行符（包括在返回值中）、EOF 或者已经读取了 length - 1
    58. 

  58.    字节后停止（看先碰到那一种情况）。如果没有指定
    59. 

  59.    <em><code class="parameter">length</code></em>，则默认为 1K，或者说 1024 字节。
    60. 

  60.       </p>
    61. 

  61.       <blockquote class="note"><p><strong class="note">Note</strong>: 
    62. 

  62.        <p class="para">
    63. 

  63.        从 PHP 4.3 开始，忽略掉
    64. 

  64.     length 则行的长度被假定为 1024，将继续从流中读取数据直到行结束。如果文件中的大多数行都大于
    65. 

  65.     8KB，则在脚本中指定最大行的长度在利用资源上更为有效。
    66. 

  66.        </p>
    67. 

  67.       </p></blockquote>
    68. 

  68.      </dd>
    69. 

  69. 

  70.     </dt>
    71. 

  71. 

  72.    </dl>
    73. 

  73. 

  74.   </p>
    75. 

  75.  </div>
    76. 

  76. 

  77. 

  78.  <div class="refsect1 returnvalues" id="refsect1-function.fgets-returnvalues">
    79. 

  79.   <h3 class="title">返回值</h3>
    80. 

  80.   <p class="para">
    81. 

  81.    从指针 <em><code class="parameter">handle</code></em> 指向的文件中读取了 <em><code class="parameter">length</code></em> - 1 字节后返回字符串。 
    82. 

  82.    如果文件指针中没有更多的数据了则返回 <strong><code>FALSE</code></strong>。
    83. 

  83.   </p>
    84. 

  84.   <p class="para">
    85. 

  85.    错误发生时返回 <strong><code>FALSE</code></strong>。
    86. 

  86.   </p>
    87. 

  87.  </div>
    88. 

  88. 

  89. 

  90.  <div class="refsect1 changelog" id="refsect1-function.fgets-changelog">
    91. 

  91.   <h3 class="title">更新日志</h3>
    92. 

  92.   <p class="para">
    93. 

  93.    <table class="doctable informaltable">
    94. 

  94.     
    95. 

  95.      <thead>
    96. 

  96.       <tr>
    97. 

  97.        <th>版本</th>
    98. 

  98.        <th>说明</th>
    99. 

  99.       </tr>
    100. 

  100. 

  101.      </thead>
    102. 

  102. 

  103.      <tbody class="tbody">
    104. 

  104.       <tr>
    105. 

  105.        <td>4.3.0</td>
    106. 

  106.        <td>
    107. 

  107.          <span class="function"><strong>fgets()</strong></span> 开始二进制安全
    108. 

  108.        </td>
    109. 

  109.       </tr>
    110. 

  110. 

  111.       <tr>
    112. 

  112.        <td>4.2.0</td>
    113. 

  113.        <td>
    114. 

  114.         <em><code class="parameter">length</code></em> 参数成为可选。
    115. 

  115.        </td>
    116. 

  116.       </tr>
    117. 

  117. 

  118.      </tbody>
    119. 

  119.     
    120. 

  120.    </table>
    121. 

  121. 

  122.   </p>
    123. 

  123.  </div>
    124. 

  124. 

  125. 

  126.  <div class="refsect1 examples" id="refsect1-function.fgets-examples">
    127. 

  127.   <h3 class="title">范例</h3>
    128. 

  128.   <p class="para">
    129. 

  129.    <div class="example" id="example-2245">
    130. 

  130.     <p><strong>Example #1 逐行读取文件</strong></p>
    131. 

  131.     <div class="example-contents">
    132. 

  132. <div class="phpcode"><code><span style="color: #000000">
    133. 

  133. <span style="color: #0000BB">&lt;?php<br />$handle&nbsp;</span><span style="color: #007700">=&nbsp;@</span><span style="color: #0000BB">fopen</span><span style="color: #007700">(</span><span style="color: #DD0000">"/tmp/inputfile.txt"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"r"</span><span style="color: #007700">);<br />if&nbsp;(</span><span style="color: #0000BB">$handle</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;while&nbsp;((</span><span style="color: #0000BB">$buffer&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">fgets</span><span style="color: #007700">(</span><span style="color: #0000BB">$handle</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">4096</span><span style="color: #007700">))&nbsp;!==&nbsp;</span><span style="color: #0000BB">false</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #0000BB">$buffer</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;(!</span><span style="color: #0000BB">feof</span><span style="color: #007700">(</span><span style="color: #0000BB">$handle</span><span style="color: #007700">))&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"Error:&nbsp;unexpected&nbsp;fgets()&nbsp;fail\n"</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">fclose</span><span style="color: #007700">(</span><span style="color: #0000BB">$handle</span><span style="color: #007700">);<br />}<br /></span><span style="color: #0000BB">?&gt;</span>
    134. 

  134. </span>
    135. 

  135. </code></div>
    136. 

  136.     </div>
    137. 

  137. 

  138.    </div>
    139. 

  139.   </p>
    140. 

  140.  </div>
    141. 

  141. 

  142. 

  143.  <div class="refsect1 notes" id="refsect1-function.fgets-notes">
    144. 

  144.   <h3 class="title">注释</h3>
    145. 

  145.   <blockquote class="note"><p><strong class="note">Note</strong>: <span class="simpara">在读取在 Macintosh 电脑中或由其创建的文件时， 如果 PHP
    146. 

  146. 不能正确的识别行结束符，启用运行时配置可选项 <a href="filesystem.configuration.html#ini.auto-detect-line-endings" class="link">auto_detect_line_endings</a>
    147. 

  147. 也许可以解决此问题。</span></p></blockquote>
    148. 

  148.   <blockquote class="note"><p><strong class="note">Note</strong>: 
    149. 

  149.    <p class="para">
    150. 

  150.     习惯了 C 语言中  <span class="function"><strong>fgets()</strong></span> 语法的人应该注意到 <em>EOF</em>
    151. 

  151.    是怎样被返回的。
    152. 

  152.    </p>
    153. 

  153.   </p></blockquote>
    154. 

  154.  </div>
    155. 

  155. 

  156. 

  157.  <div class="refsect1 seealso" id="refsect1-function.fgets-seealso">
    158. 

  158.   <h3 class="title">参见</h3>
    159. 

  159.   <p class="para">
    160. 

  160.    <ul class="simplelist">
    161. 

  161.     <li class="member"> <span class="function"><a href="function.fgetss.html" class="function" rel="rdfs-seeAlso">fgetss()</a> - 从文件指针中读取一行并过滤掉 HTML 标记</span></li>
    162. 

  162.     <li class="member"> <span class="function"><a href="function.fread.html" class="function" rel="rdfs-seeAlso">fread()</a> - 读取文件（可安全用于二进制文件）</span></li>
    163. 

  163.     <li class="member"> <span class="function"><a href="function.fgetc.html" class="function" rel="rdfs-seeAlso">fgetc()</a> - 从文件指针中读取字符</span></li>
    164. 

  164.     <li class="member"> <span class="function"><a href="function.stream-get-line.html" class="function" rel="rdfs-seeAlso">stream_get_line()</a> - Gets line from stream resource up to a given delimiter</span></li>
    165. 

  165.     <li class="member"> <span class="function"><a href="function.fopen.html" class="function" rel="rdfs-seeAlso">fopen()</a> - 打开文件或者 URL</span></li>
    166. 

  166.     <li class="member"> <span class="function"><a href="function.popen.html" class="function" rel="rdfs-seeAlso">popen()</a> - 打开进程文件指针</span></li>
    167. 

  167.     <li class="member"> <span class="function"><a href="function.fsockopen.html" class="function" rel="rdfs-seeAlso">fsockopen()</a> - Open Internet or Unix domain socket connection</span></li>
    168. 

  168.     <li class="member"> <span class="function"><a href="function.stream-set-timeout.html" class="function" rel="rdfs-seeAlso">stream_set_timeout()</a> - Set timeout period on a stream</span></li>
    169. 

  169.    </ul>
    170. 

  170.   </p>
    171. 

  171.  </div>
    172. 

  172. 

  173. </div><hr /><div class="manualnavbar" style="text-align: center;">
    174. 

  174.  <div class="prev" style="text-align: left; float: left;"><a href="function.fgetcsv.html">fgetcsv</a></div>
    175. 

  175.  <div class="next" style="text-align: right; float: right;"><a href="function.fgetss.html">fgetss</a></div>
    176. 

  176.  <div class="up"><a href="ref.filesystem.html">Filesystem 函数</a></div>
    177. 

  177.  <div class="home"><a href="index.html">PHP Manual</a></div>
    178. 

  178. </div></body></html>
    179. 

  179.