title: character array to floating point conversion
body: <p>I am trying to convert the output buffer(character array)
  of the code below to floating point format for further calculations.
  Can anybody tell me how to do it.</p>
  
  <pre><code>#include "usbtmc.h"
  #include &lt;errno.h&gt;
  #include &lt;stdio.h&gt;
  #include &lt;fcntl.h&gt;
  #include &lt;unistd.h&gt;
  #include &lt;stdlib.h&gt;
  #include &lt;getopt.h&gt;
  #include &lt;inttypes.h&gt;
  #include &lt;sys/types.h&gt;
  #include &lt;pthread.h&gt;
  
  int main() 
  {
  
      int myfile;
      char buffer[4000];
  
      int actual;
  
      myfile=open("/dev/usbtmc1",O_RDWR);
      if(myfile&gt;0)
      {
          system("echo MEAS:VOLT:AC?&gt;/dev/usbtmc1");
          actual=read(myfile,buffer,4000);
  
          buffer[actual] = 0;
          printf("Response = \n %s\n",buffer);
  
          close(myfile);
      }
  
  
      return 0;
  }
  </code></pre>
  
  <p>The sample output for this code is </p>
  
  <p><strong>Response = 
   +1.29273072E-04</strong></p>