Shell Is sh Bourne Shell or POSIX shell. What is the difference

[rcbsdpge]

Is this post historically accurate. I always thought sh shell is Bourne shell for the command line at the terminal. Or is it correct to call it Almquist shell.

Maybe the original poster is here in the forums.

https://www.reddit.com/r/freebsd/s/KeEnSa4mU5

 

[atax1a]

as we understand it, FreeBSD's POSIX-compliant shell is Bourne-compatible but was written by Almquist. "Bourne shell" is a formation by contrast with "C shell". POSIX requires that /bin/sh be Bourne-compatible, but it's OK to be a superset.

 

[T-Aoki]

Unix shell Wikipedia page.
And also builtin(1) manpage would be helpful to understand.