Compaq COBOL AAQ2G1FTK - Manual (Page 466)

Using Compaq COBOL in the Alpha Common Language Environment
13.3 OpenVMS Alpha System Routines (OpenVMS)
13.3.1 OpenVMS Alpha Run-Time Library Routines
The OpenVMS Alpha Run-Time Library provides commonly used routines that
perform a wide variety of functions. These routines are grouped according to the
types of tasks they perform, and each group has a prefix that identifies those
routines as members of a particular OpenVMS Alpha Run-Time Library facility.
Table 13–2 lists all the language-independent Run-Time Library facility prefixes
and the types of tasks each facility performs.
Table 13–2 Run-Time Library Facilities (OpenVMS)
Facility Prefix Types of Tasks Performed
CVT$ Library routines that handle floating-point data conversion
DTK$ DECtalk routines that are used to control a Compaq DECtalk device
LIB$ Library routines that:
Obtain records from devices
Manipulate strings
Convert data types for I/O
Allocate resources
Obtain system information
Signal exceptions
Establish condition handlers
Enable detection of hardware exceptions
Process cross-reference data
MTH$ Mathematics routines that perform arithmetic, algebraic, and
trigonometric calculations
OTS$ General-purpose routines that perform tasks such as data type
conversions as part of a compiler’s generated code
PPL$ Parallel processing routines that help you implement concurrent
programs on single-CPU and multiprocessor systems
SMG$ Screen management routines that are used in designing, composing,
and keeping track of complex images on a video screen
STR$ String manipulation routines that perform such tasks as searching for
substrings, concatenating strings, and prefixing and appending strings
13.3.2 System Services
System services are prewritten system routines that perform a variety of tasks,
such as controlling processes, communicating among processes, and coordinating
I/O.
Unlike the Run-Time Library routines, which are divided into groups by facility,
all system services share the same facility prefix (SYS$ on OpenVMS Alpha or
SYS_ on Tru64 UNIX). However, these services are logically divided into groups
that perform similar tasks. Table 13–3 describes these groups.
Table 13–3 System Services (OpenVMS)
Group Types of Tasks Performed
AST Allows processes to control the handling of asynchronous system
traps
Change Mode Changes the access mode of particular routines
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13–4 Using Compaq COBOL in the Alpha Common Language Environment