Taos does not currently emulate Ultrix sockets. This is an expedient rather than fundamental omission: adding sockets (the basic machinery, together with one more actual network interfaces) would not present any unusual difficulty and would add useful functionality (e.g., convenient access to VMS machines via DECnet). In the mean time, Taos includes a fairly comprehensive RPC implementation together with facilities that use it (including remote debugging, file access, display access, and login).
On Taos, the following socket-related kernel calls always raise SIGSYS: accept, bind, connect, getpeername, getsockname, getsockopt, listen, recv, recvfrom, recvmsg, send, sendmsg, sendto, setsockopt, shutdown, socket, and socketpair.
Taos implements the gethostname kernel call by calling NSUtil.GetMyHost. It implements the sethostname kernel call by always returning EPERM.
Ultrix commands that use sockets won't work on Taos. Alternatives for the most common are available: monarch for rlogin, msh for rsh, and cp or the more efficient copy for rcp. There is no direct analogue for rdist, but several programs provide similar functionality. The copy command maintains time stamps and subdirectory structure. The updatefs command maintains consistency between the `GF' file system and a local Firefly file system. The `package tools' (getpackage, shippackage, etc.) facilitate sharing `project' subdirectories among a set of developers. (See also vget(1), vlink(1), and vship(1).)