somehow the opengroup removed egrep and fgrep from POSIX in 2018 https://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xcu...

chroot, usefull for poor man's containment of 'stuff' also went out.

and they replaced tar with pax --- which uses a tar file format

one of the things I love in Unix is the slow pace of evolution in systems tools. relevant know how doesn't rot as fast as in other environments.