Specifications

The ULTRIX Operating System, Version 4.5 SPD 26.40.32
DEC C provides support for the American National Stan-
dards (ANSI) definition of the C programming language,
ANSI X3J11/88-159. DEC C has passed the Plum Hall
test suite.
Using the command line options, DEC C is compati-
ble with older dialects of C, including common (K&R
1
)
C and VAX C. The compiler also provides support for
function inlining to eliminate call overhead and source
code checking features such as those found in the lint(1)
utility for assistance in identifying nonportable or unin-
tended coding practices.
In addition to the language, the ANSI C standard also
defines the contents of the C library and defining header
files.
The documentation for DEC C is provided in hardcopy
form and online via the Bookreader. The online man(1)
command provides access to the c89 and cpp89 man-
pages for the compiler and preprocessor, respectively.
The documents are provided in hardcopy form with the
Media kit and in online form on the ULTRIX Online Doc-
umentation (OLD) disc.
ULTRIX and ULTRIX Worksystem Software (UWS) in-
clude a license for DEC C. The binaries and documen-
tation are not included in the operating system media,
and must be ordered as a separate DEC C Media and
Documentation package. Refer to the
SOFTWARE OP-
TIONS
section for ordering information.
•
CDA Toolkit
The CDA Toolkit is an object library that provides the
data structures and routines used to create, store, and
interchange the revisable file formats supported by CDA
(Compound Document Architecture). The CDA Toolkit
is used to create CDA-compliant applications, or to write
converters that will interchange existing file formats us-
ing CDA data structures as the intermediate format.
Migration to and from the CDA environment includes
portability across the ULTRIX RISC, ULTRIX VAX and
VMS Operating Systems. Electronic mailing and copy-
ing of revisable CDA documents provide support for
hardware- and system-independent display and print-
ing.
CDA data structures are predefined aggregate types
that store, in memory, all the items needed to encode
DDIF and DTIF documents. DDIF (Digital Data Inter-
change Format) aggregates are used to create CDA-
compliant compound documents, graphics and image
documents, or converters. DTIF (Digital Table Inter-
change Format) aggregates are used to create CDA-
compliant table data documents or converters for use
by spreadsheet and database applications.
CDA data structures are used by supplying the appro-
priate information for all the items stored in each aggre-
gate. The way the data structures are linked using the
CDA routines determines the structure of the documents
created by supporting applications.
CDA routines perform multiple operations including file,
stream, and aggregate management; item storage and
access; and reading, writing, and conversion of CDA
data structures. Calls to the CDA routines are encoded
within an application source file.
Converters bundled with the CDA Toolkit are: the
DDIF, DTIF, and Text input and output converters; a
PostScript® output converter; and an Analysis output
converter which is a debugging tool that produces text
output of CDA in-memory data structures.
Digital encourages independent software vendors to use
the CDA Toolkit and its converter architecture to write
new converters. The CDA Converter Architecture pro-
vides the advantage of a standard hub of interchange
so all CDA-compliant converters, whether developed by
Digital or independent software vendors, can participate
in data exchange.
The CDA Viewer, also bundled with the CDA Toolkit,
displays the contents of all CDA-supported documents
on a UWS workstation or character-cell terminal.
Callable DECwindows and character-cell viewer rou-
tines are used to write portable viewer widgets.
•
DECthreads
ULTRIX includes a user-mode multi-threading capabil-
ity referred to as DECthreads. DECthreads provides
an implementation of draft 4 of the proposed POSIX
1003.4a Standard. DECthreads is a library of run-time
routines callable from a C program that allows the user
to create multiple threads of execution within a single
address space. Multi-threading capability allows com-
putation activity to be overlapped with I/O activity. Syn-
chronization elements, such as mutexes and condition
variables, are provided to help ensure that shared re-
sources are accessed correctly. DECthreads also pro-
vides multiple scheduling policies for scheduling and pri-
oritizing threads.
User Features
User Interfaces
• Shells . ULTRIX provides the following shells:
- C Shell
- BSD™ Bourne Shell
- System V Bourne Shell
- Korn Shell
All shells are programmable and allow for a tailorable
user environment.
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