> the shell’s semantics is black magic, specified in a 119page impenetrable document that is the POSIX shell specification (with an extra 160pp on utilities!).

> the shell’s semantics is black magic, specified in a 119page impenetrable document that is the POSIX shell specification (with an extra 160pp on utilities!). That's academia going pedantic and mystifying things right there. Strict POSIX compliance was never that important to most people. I never read the POSIX shell specification and never needed it. Writers of shells like bash or ksh probably did and apparently managed this "black magic" well enough to make their shells work well. You can learn shell programming by yourself, from bash manpage and examples used in Linux systems. It's not rocket science. Computer languages get adopted not because they have nice and simple spec, but despite not having a neat and simple spec. It's like with natural languages. There is no authority and no simple spec. And it's not an important problem.