title: Environment path set to "PATH" variable missing after system restart?
body: <p>I have set </p>
  
  <pre><code>export PATH=$PATH:/home/user/android-sdk-linux/platform-tools
  </code></pre>
  
  <p>and execute the above line in command line and later if I type echo $PATH, I could see the path added. But after restarting the system I couldn't see it any more. But putting the system to sleep and then starting again, I could still see it. How to resolve the issue?</p>