AM3270 and TR3271 Configuration and Management Manual

SCF Interface to AM3270 and TR3271

AM3270 and TR3271 Configuration and Management Manual—529993-001

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How SCF Works

For commands that relate only to the SCF session (such as VOLUME), SCF takes the

appropriate action without communicating with SCP. For commands that relate to a

subsystem or its objects, SCF translates the command into a formatted message for

SCP, which then communicates with the appropriate subsystem to perform the

specified task.

SCF accepts commands from a terminal, a disk file, or an application process. It sends

display output to a terminal, a file, a process, or a printer. When SCF is started

interactively, the input source and output destination are specified in the command-

interpreter RUN command used to start SCF. If SCF is started by a NonStop

Kernel process-creation procedure, its input source and output destination are taken

from the startup message. Subsequent SCF commands can change the input source

and output destination.

Input Sources

SCF accepts command input from a terminal or a disk file. The initial input source is

determined by the form of the RUN command used to initiate SCF. At any time during

an SCF session, the input source can be temporarily changed to execute a series of

commands from a command file.

Modes of Operation

SCF can be run in two modes: interactive or noninteractive. Because interactive and

noninteractive input are treated differently by SCF, the following distinctions are

important:

•

The mode is interactive when both input and output pass through the same

terminal, or when the same process is used for both input and output. For instance,

using the OUT command or the / OUT file-spec / parameter within a command

causes SCF to run in noninteractive mode. This distinction affects the use of

abbreviations when you enter keywords: abbreviations (formed by truncating

keywords, provided the result is unambiguous) are permitted in interactive mode

only. For example, in noninteractive mode you can abbreviate the VERSION

command to VE, but in a command file you must spell out VERSION.

•

Interactive input from a terminal is characterized by the entry of a command

followed by a carriage return. When a process is used for both input and output,

SCF waits for the process to send a request and treats the process in the same

manner as a terminal.

•

Noninteractive input usually appears in the form of a command file. Command files

are usually EDIT files that contain a series of commands.