Wondering why the POSIX shell behaves the way it does? We can expand and evaluate shell code according to the POSIX standard. You can symbolically configure your shell and operating system environment.
Commands are limited to the core shell builtin operations described in Section 2.9.1 Command Search and Execution of the POSIX spec.
|unexpanded words||initial state|
|expanded words||before field splitting|
|temporary field||before pathname expansion|
|fully expanded field||final state|