title: Implicit declaration of function basename in linux
body: <p>i am using basename() function in my code.
  Where i am including </p>
  
  <pre><code>#include &lt;unistd.h&gt;
  </code></pre>
  
  <p>and when i m compiling that code with -Wall flag it shows </p>
  
  <p>following warning </p>
  
  <pre><code>warning: implicit declaration of function ‘basename’
  </code></pre>
  
  <p>if i am writing its declaration in my code </p>
  
  <pre><code>char * basename (const char *fname);
  </code></pre>
  
  <p>then it does not show that warning</p>
  
  <p>why this happening.?</p>