Re:Unix Shell Programming: The Next 50 Years [pdf]
by gnubison on Saturday June 05, 2021 @11:45PM
(#27410611)
Those work in any POSIX shell, and also zsh.
Re:Unix Shell Programming: The Next 50 Years [pdf]
by teddyh on Monday June 07, 2021 @07:54AM
(#27421473)
It seems you are correct:
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V...
In Bash it’s
or