The lowest level of abstraction in the tool control layer of the
VISTA/SFC environment is represented by the System Tool Interface
(STI) ,
that provides access to system executables in a uniform way.
The purpose of this interface is to hide details of tool invocation
that are related to queuing systems, file location of executables,
authorized hosts for a given executable, and site-specific invocation
procedures; basic logging and work-in-progress facilities
are also offered. In this way, external tools can be accessed by
symbolic names throughout all source code files and user-defined
task-level applications.
The actual mapping from the symbolic name to
the operating system's command line is defined in a central
configuration file
.