title: undefined reference to `crypt'
body: <p>I am using the below code that i found somewhere in the net and i am getting an error when i try to build it. The compilation is ok.</p>
  
  <p>Here is the error:</p>
  
  <pre><code>/tmp/ccCnp11F.o: In function `main':
  
  crypt.c:(.text+0xf1): undefined reference to `crypt'
  
  collect2: ld returned 1 exit status
  </code></pre>
  
  <p>and here is the code:</p>
  
  <pre><code>#include &lt;stdio.h&gt;
   #include &lt;time.h&gt;
   #include &lt;unistd.h&gt;
   #include &lt;crypt.h&gt;
  
   int main()
   {
     unsigned long seed[2];
     char salt[] = "$1$........";
     const char *const seedchars =
       "./0123456789ABCDEFGHIJKLMNOPQRST"
       "UVWXYZabcdefghijklmnopqrstuvwxyz";
     char *password;
     int i;
  
     /* Generate a (not very) random seed.
        You should do it better than this... */
     seed[0] = time(NULL);
     seed[1] = getpid() ^ (seed[0] &gt;&gt; 14 &amp; 0x30000);
  
     /* Turn it into printable characters from `seedchars'. */
     for (i = 0; i &lt; 8; i++)
       salt[3+i] = seedchars[(seed[i/5] &gt;&gt; (i%5)*6) &amp; 0x3f];
  
     /* Read in the user's password and encrypt it. */
     password = crypt(getpass("Password:"), salt);
  
     /* Print the results. */
     puts(password);
     return 0;
   }
  </code></pre>