title: GIT Ignore already commited files using exclude for local changes
body: <p>I cloned the remote repository which is having three files</p>
  
  <pre><code>file1.txt 
  file2.txt
  file3.txt
  </code></pre>
  
  <p>changes are made locally in my machine into file3.txt. I don't want the changes to go into remote repo and vice versa.</p>
  
  <p>I read that using .gitignore it is not possible to ignore the already commited and tracked file.</p>
  
  <p>I decided to use .git/info/exclude file with the following line</p>
  
  <p><strong>exclude file</strong></p>
  
  <pre><code>file3.txt
  </code></pre>
  
  <p>But still changes made in file3.txt are shown as unstaged file. I want this file3.txt to be ignored in commit and staging and also need to prevent file3.txt to update from remote repo </p>
  
  <p>Thanks in advance for any help</p>