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  47. <a name="gets"></a>
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  49. <p>
  50. Next: <a href="getw.html#getw" accesskey="n" rel="next">getw</a>, Previous: <a href="getline.html#getline" accesskey="p" rel="prev">getline</a>, Up: <a href="Stdio.html#Stdio" accesskey="u" rel="up">Stdio</a> &nbsp; [<a href="Document-Index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Document-Index.html#Document-Index" title="Index" rel="index">Index</a>]</p>
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  53. <a name="gets_002d_002d_002dget-character-string-_0028obsolete_002c-use-fgets-instead_0029"></a>
  54. <h3 class="section">4.39 <code>gets</code>&mdash;get character string (obsolete, use <code>fgets</code> instead)</h3>
  55. <a name="index-gets"></a>
  56. <a name="index-_005fgets_005fr"></a>
  57. <p><strong>Synopsis</strong>
  58. </p><div class="example">
  59. <pre class="example">#include &lt;stdio.h&gt;
  60. char *gets(char *<var>buf</var>);
  61. char *_gets_r(struct _reent *<var>reent</var>, char *<var>buf</var>);
  62. </pre></div>
  63. <p><strong>Description</strong><br>
  64. Reads characters from standard input until a newline is found.
  65. The characters up to the newline are stored in <var>buf</var>. The
  66. newline is discarded, and the buffer is terminated with a 0.
  67. </p>
  68. <p>This is a <em>dangerous</em> function, as it has no way of checking
  69. the amount of space available in <var>buf</var>. One of the attacks
  70. used by the Internet Worm of 1988 used this to overrun a
  71. buffer allocated on the stack of the finger daemon and
  72. overwrite the return address, causing the daemon to execute
  73. code downloaded into it over the connection.
  74. </p>
  75. <p>The alternate function <code>_gets_r</code> is a reentrant version. The extra
  76. argument <var>reent</var> is a pointer to a reentrancy structure.
  77. </p>
  78. <br>
  79. <p><strong>Returns</strong><br>
  80. <code>gets</code> returns the buffer passed to it, with the data filled
  81. in. If end of file occurs with some data already accumulated,
  82. the data is returned with no other indication. If end of file
  83. occurs with no data in the buffer, NULL is returned.
  84. </p>
  85. <p>Supporting OS subroutines required: <code>close</code>, <code>fstat</code>, <code>isatty</code>,
  86. <code>lseek</code>, <code>read</code>, <code>sbrk</code>, <code>write</code>.
  87. </p>
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