Permissions corrupted in OS X I have run sudo chown -R Ankur / by mistake and now some apps are not opening and there icons are also not visible. How can I fix this?

Here are some snapshots:
Short term, you can turn off Gatekeeper to allow the application you corrupted to run. 


Open system preferences
Select Security &amp; Privacy
Select general
Select Anywhere


The system should have protected most of the command line tools, but I would see if you can make one last back up of the system and then restore the OS if applications installed by the system are messed up.

Specifically, my Macbook has 60 million files - so had I run that command, I would have a lot of work to do to ensure everything is correct and staring with deleting all apps I can easily reinstall and then reinstalling the system if I broke any system apps is far shorter a path to recovery.

Luckily - all your personal files were already owned by your user, so this exercise in recovery will be to get copied of apps that are not unique to your system and at worst, you'll need to delete preference and configuration files and re-create them if they need permissions different than what you enforced on your system.