How to create a Case Sensitive filesystem in 10.11.1? How to create a Case Sensitive file system on a Mac?

Here is a simple test:

echo 'you should see this' &gt; abc ; echo 'not just this twice' &gt; ABC ; cat  abc ABC
you should see this
not just this twice


I'm on Mac version 10.11.1 and even with a "Case Sensitive" filesystem on a DMG image, I get:

not just this twice
not just this twice
It looks like there is a bug in the newly-rewritten Disk Utility application in El Capitan (as of 10.11.2) where it can't create case-sensitive disk images. As your answer mentioned, you can use the hdiutil command-line tool as a workaround; alternately, in Disk Utilty, you can erase the disk image after creating it, selecting a case-sensitive format.

https://discussions.apple.com/thread/7395900