                       QUIET BATCH FILES

Normally commands in a BATCH file are displayed ("echoed") on the screen as 
they are processed by COMMAND.COM. Frequently it is desirable to suppress 
such displays. Since ECHO ON is assumed at the beginning of each batch file 
by COMMAND.COM, the first statement in many batch files is 

	ECHO OFF

Such a batch file is called a "quiet" batch file. Of course, this statement 
is displayed. 

There are four ways to suppress even this single display. The most drastic 
is to patch or modify the COMMAND.COM program, so that it assumes ECHO OFF 
at the beginning of each batch file. The second way (available only in DOS 
3.3 and later) is to put an @ character in front of the initial ECHO OFF 
command. The third way can be used with any level of DOS, provided that the 
line DEVICE=ANSI.SYS is present in the CONFIG.SYS file. The following 
commands at the beginning of a batch file will erase the ECHO OFF statement 
from the screen almost immediately.

	ECHO OFF
	ECHO ^[[80D^[[A^[[K^[[A

The effect of "^[" (the ESC character) in the second ECHO command is explained 
in the PROMPT ESCAPE_SEQUENCES topic. In OS/2 only, a /Q option can be added 
to the command line executing the batch file.

To further reduce output to the screen, some messages from DOS commands and 
other programs can be redirected to the NUL: device name. For example, 

	COPY OLD NEW > NUL

will copy OLD to NEW as usual, but the status message 

	1 File(s) copied 

will not be displayed on the screen. A wholesale elimination of screen 
displays by the batch file is possible by including the statement

	CTTY NUL

near the beginning of the file. All output will be redirected to the NUL
device. Also, all input is expected to come from the NUL device, so if any
program in the batch file expects input from the keyboard, put the line

	CTTY CON

in front of it. The above line must also be executed before the batch file
terminates. Otherwise, you must reboot the system.
