Interesting case of /proc and /dev on POSIX systems
TL;DR If you want to have a good read, I’d recommend skipping the TL;DR segment. You might miss some fun when reading the article if you read this out. You’ve been warned. /dev/stdin, /dev/stdout, and /stderr are not required to be implemented by the POSIX standard, but are listed as POSIX extensions. Similarly, /proc (or the procfs) is also just listed as an extension just once in the POSIX standard, with no mention of what things need to be there inside. ...