Digital UNIX Version 4.0 supports the following two System V packages in an effort to provide users, programmers, and administrators with complete System V Release 4 functionality:
The System V Compatibility habitat ships with the base system and, in conjunction with the work done to extend the Digital UNIX Version 4.0 libraries to contain System V functionality, allows Digital UNIX Version 4.0 to conform to the following two volumes from the four volumes listed in the System V Interface Definition 3 (SVID 3):
Note that NeWS Windows is not supported.
The
System V Compatibility habitat
consists of several commands in the
/usr/opt/s5
directory
(commands that are commonly used in shell scripts
and that format their data differently from the
corresponding
Digital UNIX
commands)
as well as
a separate
System V shared and static
library
(libsys5.a
and
libsys5.so)
that contains functions that are different from
those already in the
standard
libc.
For the most part,
however,
Digital has attempted to extend the functions and system
calls in
libc
to include the necessary System V functionality and behavior
so that many programs written for System V can
compile and run on
Digital UNIX Version 4.0
without the need to link against
libsys5.
Also,
Digital has added
the
swapctl
and
memcntl
System V system calls
to
libc
as well as
support for
the
System V
pseudodevice,
/dev/zero,
the
/proc
file system,
the
FDFS
file system,
SVR4 signals,
and
SVR4 STREAMS.
Users and programmers can access the
Digital UNIX Version 4.0
System V Compatibility habitat
either by
placing the
/usr/opt/s5
path in their
.profile
file
or by using the
absolute pathname
for this directory.
The
cc
and
ld
commands in
the
/usr/opt/s5
directory
for example,
are in fact shell wrappers
which, when called,
search the
libsys5.a
and
libsys5.so
libraries
before looking in
libc,
so that programmers
can access these libraries transparently.
For more information on the System V Compatibility habitat, see the System Administration guide , Programmer's Guide, and the Command and Shell User's Guide.
The System V Environment extends the functionality provided by the System V Compatibility habitat by supporting a more complete System V Release 4 (SVR4) environment for general users, application programmers, and system administrators. The System V Environment is an extension to the operating system that contains a separate System V Release 4.0 binary license from UNIX Software Laboratories and requires a special license and a Product Authorization Key (PAK) to access.
The System V Environment extends the base system SVID 3 compliance to provide complete compliance to the SVID 3 standard, by supporting the following two additional SVID 3 volumes:
See Figure 9-1 for a summary of SVID support in both Digital UNIX and the System V Environment.
In addition, the System V Environment meets operating system requirements critical to the telecommunications industry, as defined in the Bellcore Standard Operating Environment (SOE), Issue 2.
The System V Environment supports the following functionality:
pkg*
commands)
The System V Environment
delivers the complete suite of SVR4 commands
as well as
the
libsvr4
library,
which contains
all the
SVR4
routines for the base system.
Essentially,
the
System V Environment
extends the functionality of the
System V Compatibility habitat,
allowing users, programmers, and administrators
to work in a completely native
System V environment, without the
Digital UNIX
"look and feel."
However,
through
manipulating
each user's
.profile
file,
each environment,
System V and
Digital UNIX ,
can be accessed
without difficulty
and,
with the exception of the
Printing Subsystem,
without reconfiguring
the system.
Note that
programmers
can develop and run both
Digital UNIX
and SVR4 applications simultaneously,
no matter which environment they choose to adopt.
For more information
on the
System V Environment,
see the
System V Environment for Digital UNIX Version 4.0 User's Guide
and the
SVR4 to SVE for Digital UNIX Version 4.0 Migration Guide.