title: How to use otool to check for whether Stack Smashing is enabled or not?
body: <p>I see many answers, like <a href="https://stackoverflow.com/a/43554731/3003927">this</a>, and <a href="https://forums.developer.apple.com/thread/86355" rel="nofollow noreferrer">this</a> on the internet says to use <code>otool</code> command to check for <code>stack_chk_guard</code> and <code>stack_chk_fail</code> on the project.</p>
  
  <p>The problem is, I don't know to which <em>file</em> the otool must be applied. On a <a href="http://iosbrain.com/blog/2017/01/07/the-heartbreak-of-the-xcode-undefined-symbols-for-architecture-xxx-linker-message/#more-7" rel="nofollow noreferrer">source</a>, they say this <code>otool</code> is to be applied on a file with extension <code>.a</code>, which is a library. But I don't know how that can be applied to my situation where I want to check the <em>whole</em> project, not just a library. And I tried to find any file within my project with <code>.a</code> extension, and I found none. I've tried to run <code>otool</code> against <code>.app</code>, <code>.framework</code>, <code>.xcarchive</code>, and <code>.ipa</code>, all failed.</p>
  
  <p>Can somebody help? Please be elaborate if necessary, because I never use <code>otool</code> before, and documentations on the internet doesn't help at all when it comes to describe what files can be checked by <code>otool</code>.</p>