title: Understanding Linux directory permissions reasoning
body: <p>Hi I have 2 questions regarding linux directory permissions which I do not understand.</p>
  
  <p>I removed the execute flag from a folder named Documents. After that I cannot use cd on it but I still can do "ls Documents" from the parent directory and it still lists me the files in the Documents directory. 
  I though the missing x-flag denies reading this directory?</p>
  
  <p>Then I want to know for why the sticky bit on directories was invented. I've heard it was used so that users cannot delete temp-files creates by other users. But this IMO violates the rule that for deletion of files we just need rights for this directory. Why not simply give each user a separate /tmp/ directory instead of introducing exceptions in the rule system? 
  I know what the flag does, but I want to know the reasoning on why is was invented.</p>