title: Change permission of file owned by root-user without using sudo
body: <p>I have a file owned by "root" and script owned by "non-root" user. I'm trying to change permission of "root" owned file using "non-root" script and getting below error:</p>
  
  <pre><code>$ cat root_file
  echo "HELLO WORLD"
  
  $ cat non_root_script
  chmod 777 root_file.txt
  
  $ ./non_root_script
  chmod: changing permissions of 'abc.txt': Operation not permitted
  </code></pre>
  
  <p>I tried adding capabilities to the non_root_script but I'm still getting same error.</p>
  
  <pre><code>$ sudo setcap CAP_FOWNER+ep non_root_script
  $ ./non_root_script
  chmod: changing permissions of 'abc.txt': Operation not permitted
  </code></pre>
  
  <p>Are there any other capabilities that I need to provide, if so please suggest. Also I don't want to use "sudo chmod".</p>