title: how to determine if two file are identical in c using system call
body: <p>i need to see if 2 files are identical
  so i used 
  struct stat</p>
  
  <pre><code>    fdin = open(argv[0],O_RDONLY);
      statos= fstat(fdin, &amp;stat);
      close(fdin);
      fdin = open(argv[1],O_RDONLY);
      statos1= fstat(fdin, &amp;stat1);
      close(fdin);
      printf("file 1 is in size: %lu\n",stat1.st_ino);
      printf("file 2 is in size: %lu\n",stat.st_ino);
  </code></pre>
  
  <p>the result</p>
  
  <pre><code>file 1 is in size: 9569486
  file 2 is in size: 9569479
  </code></pre>
  
  <p>why is the st.ino aren't identical for the same file with the same path??
  and how can i do so if two different file are identical i could check it with system call</p>