I did some archeology. OpenBSD also support -b in the same way as InetUtils and NetKit: https://man.openbsd.org/telnet.1
FreeBSD uses -s instead: https://www.freebsd.org/cgi/man.cgi?query=telnet NetBSD, OpenSolaris and AIX supports neither of -s and -b, and fortunately does not appear to use them for anything else: https://man.netbsd.org/telnet.1 https://www.unix.com/man-page/opensolaris/1/telnet/ https://www.ibm.com/docs/en/aix/7.2?topic=t-telnet-command /Simon
signature.asc
Description: PGP signature
