In some versions of the Unix operating system, the term universe was used to denote some variant of the working environment. During the late 1980s, most commercial Unix variants were derived from either System V or BSD. Some versions provided both BSD and System V universes and allowed the user to switch between them. Each universe, typically implemented by separate directory trees or separate filesystems, usually included different versions of commands, libraries, man pages, and header files. While such a facility offered the ability to develop applications portable across both System V and BSD variants, the requirements in disk space and maintenance (separate configuration files, twice the work in patching systems) gave them a problematic reputation[citation needed].
Systems that offered this facility included Control Data Corporation's EP/IX[1], Harris/Concurrent's CX/UX[citation needed], Convex's ConvexOS[2], Apollo's Domain/OS (version 10 only)[3], Pyramid's DC/OSx (dropped in SVR4-based version 2)[citation needed], Concurrent/MASSCOMP's Masscomp/RTU[4], MIPS Computer Systems' RISC/os[5], Sequent's DYNIX[6] and Siemens' SINIX[6].
Some versions of System V Release 4 (such as Solaris) retain a system similar to the universe concept, with BSD commands (which behave differently from classic System V commands) in /usr/ucb, BSD header files in /usr/ucbinclude and library files in /usr/ucblib[7]. /usr/ucb can also be found in NeXTSTEP and OPENSTEP[8].
References
- ^ Meerwaldt, Freddy (2003-08-24). "EP/IX software porting guide". cray-cyber.org. Retrieved 2025-12-02.
EP/IX is a hybrid[...] it can either act like a SysV UNIX or a BSD 4.3 UNIX
- ^ Schweisguth, Dave (1995-04-29). "TCSH(1) Builtin commands#warp". University of California, Santa Barbara Physics Computing Services (PCS). Retrieved 2025-12-02.
warp universe (+) Sets the universe to universe. (Convex/OS only)
- ^ Mascheck, Sven (2022-01-01). "Various system shells". arbitrary unix stuff. Retrieved 2025-12-02.
DomainOS 10.4 offers two socalled universes: "bsd4.3" and "sys5.3"
- ^ Schweisguth, Dave (1995-04-29). "TCSH(1) Builtin commands#universe". University of California, Santa Barbara Physics Computing Services (PCS). Retrieved 2025-12-02.
universe universe (+) Sets the universe to universe. (Masscomp/RTU only)
- ^ Thoryk, Ryan (2020-10-07). "History of IRIX". ryan.thoryk.com. Retrieved 2025-12-02.
MIPS computers running RISC-OS can support four different personalities: default, BSD 4.3, System V.3, and System V.4
- ^ a b Mascheck, Sven (2022-01-01). "DYNIX 3.2.0 and SINIX V5.20 Universes". arbitrary unix stuff. Retrieved 2025-12-02.
- ^ "Are /usr/ubc[sic] binaries different than /usr/bin binaries?". Oracle Corporation. 2007-09-16. Retrieved 2025-12-02.
usr/ucb/ gives some behavior of older BSD systems for compatibility.
- ^ "NeXTSTEP source code. usr.ucb Directory Reference". Retrieved 2025-12-02.
External links
- Sven Mascheck, DYNIX 3.2.0 and SINIX V5.20 Universes
