macOS is BSD Unix under the hood with the Mach kernel [1]. I'm tired of hearing this nonsensical talking point that macOS has strayed too far to be considered Unix. What does that even mean? Perhaps someone should inform The Open Group who controls the official Unix specification that they are wrong. Even though it shells like a unix, users like a unix, signals like a unix, files like a unix, networks like a unix, streams like a unix, and threads like a unix, because of reasons never enumerated, macOS is not Unix. /endrant

[1] https://developer.apple.com/library/mac/documentation/MacOSX...