title: how can i know the allocated memory size of pointer variable in c
body: <p>I have faced some problem in this case can you please your ideas.</p>
  
  <pre><code>main()
  {
  char *p=NULL;
  p=(char *)malloc(2000 * sizeof(char));
  printf("size of p = %d\n",sizeof (p));
  }
  </code></pre>
  
  <p>In this program Its print the 4 that (char *) value,but i need how many bytes allocated for 
  that.</p>