Looking-Up-or-Entering-a-String.html 5.0 KB

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  69. <a name="Looking-up-or-entering-a-string"></a>
  70. <h4 class="subsection">2.18.2 Looking up or entering a string</h4>
  71. <a name="index-bfd_005fhash_005flookup"></a>
  72. <p>The function <code>bfd_hash_lookup</code> is used both to look up a
  73. string in the hash table and to create a new entry.
  74. </p>
  75. <p>If the <var>create</var> argument is <code>FALSE</code>, <code>bfd_hash_lookup</code>
  76. will look up a string. If the string is found, it will
  77. returns a pointer to a <code>struct bfd_hash_entry</code>. If the
  78. string is not found in the table <code>bfd_hash_lookup</code> will
  79. return <code>NULL</code>. You should not modify any of the fields in
  80. the returns <code>struct bfd_hash_entry</code>.
  81. </p>
  82. <p>If the <var>create</var> argument is <code>TRUE</code>, the string will be
  83. entered into the hash table if it is not already there.
  84. Either way a pointer to a <code>struct bfd_hash_entry</code> will be
  85. returned, either to the existing structure or to a newly
  86. created one. In this case, a <code>NULL</code> return means that an
  87. error occurred.
  88. </p>
  89. <p>If the <var>create</var> argument is <code>TRUE</code>, and a new entry is
  90. created, the <var>copy</var> argument is used to decide whether to
  91. copy the string onto the hash table objalloc or not. If
  92. <var>copy</var> is passed as <code>FALSE</code>, you must be careful not to
  93. deallocate or modify the string as long as the hash table
  94. exists.
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