| SAS Companion for UNIX Environments |
UNIX is a multitasking
system, so you can run multiple processes at the same time. For example, you
can have one process running in the foreground and three in the background.
A foreground process executes while you wait for the
prompt; that is, you cannot execute additional commands while the current
command is being executed. After you enter a command, the shell starts a process
to execute the command. After the system executes the command, the shell displays
the prompt and you can enter additional commands. A background process executes independently of the shell. After you enter a command,
the shell starts a process to execute the command and then issues the system
prompt. You can enter other commands or start other background tasks without
waiting for your initial command to execute. You can run the SAS System in
the foreground or in the background.
Note: Both the C shell and the Korn shell include commands
that allow you to move jobs among three possible states: running in the foreground,
running in the background, and suspended. ![[cautionend]](../common/images/cautend.gif)
You can run SAS in the SAS windowing environment, in
interactive line mode, or in batch mode.
-
Windowing environment
- You interact with SAS through windows using
your keyboard, mouse, pull-down menus, pop-up menus, and icons. The windowing
environment includes, but is not limited to, the Explorer, Program Editor,
Output, Log, and Results windows. Explorer is a windowing environment for
managing basic SAS software tasks such as viewing and managing data sets,
libraries and members, applications, and output. The SAS Explorer is a central
access point from which you can
- manipulate SAS data through a graphical interface
- access the Program Editor, Output,
and Log windows
(as well as other windows)
- view the results of SAS procedure output in the
Results window
- import files into the SAS System.
The Program Editor, Log, and Output windows enable you to
edit and execute SAS programs and display output.
If you want to use the windowing environment, you can
start your SAS session as a foreground process or as a background process
(by adding an ampersand (&) to your SAS command line).
- Interactive line mode
-
You enter SAS statements line by line in response to prompts
issued by the SAS System. SAS reads the source statements from the terminal
as you enter them. DATA and PROC steps execute when
- a RUN, QUIT, or DATALINES statement is entered
- another DATA or
PROC statement is entered
- the ENDSAS statement is entered.
To use interactive line mode, you must run SAS in the
foreground.
- Batch mode
-
To run SAS in batch mode, you specify your SAS application name
in the SAS command. You can run batch mode in the foreground, in the background
by specifying an ampersand at the end of the SAS command, or submit your application
to the batch queue by using the
batch,
at,
nohup,
or
cron UNIX commands. If you start your
application with one of these UNIX commands, then you log off of your system
and your application will complete execution. If your application contains
statements that start an interactive procedure such as FSEDIT, then you need
to run your batch application in the foreground.
Ask your system manager which interface or mode of
operation is the default at your site.
Copyright 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
