From a Basic program, you can invoke the SHELL statement to execute an
MS-DOS command. Normally, many MS-DOS commands give you a confirmation
message. If you want to suppress the message (thus making the SHELL
operation less visible), you can redirect the standard MS-DOS output
to the NUL device.
Here is an example:
SHELL "copy file1 file2 > NUL"
The above statement copies file1 to file2 and redirects the success
report "1 file(s) copied" to the NUL device, which is never displayed.
You may do the same redirection to prevent the DOS success report from
printing on the printer (PRN) device:
SHELL "copy file1 PRN > NUL"
The above information applies to the following products:
- Microsoft QuickBasic versions 2.00, 2.01, 3.00, 4.00, 4.00b,
and 4.50 for the IBM PC
- Microsoft Basic Compiler versions 6.00 and 6.00b for MS OS/2
and MS-DOS
- Microsoft Basic Professional Development System (PDS) versions 7.00
and 7.10 for MS-DOS and MS OS/2
- Microsoft GW-Basic Interpreter versions 3.20, 3.22, and 3.23
for MS-DOS
In MS-DOS, the greater-than sign, ">", redirects standard output to
standard input. The less-than sign, "<", redirects standard input to
standard output.
Article ID: 40592 - Last Review: August 16, 2005 - Revision: 2.1
APPLIES TO
- Microsoft BASIC Compiler 6.0
- Microsoft BASIC Compiler 6.0b
- Microsoft QuickBasic 4.0
- Microsoft QuickBASIC 4.0b
- Microsoft QuickBasic 4.5 for MS-DOS
- Microsoft BASIC Professional Development System 7.0
- Microsoft BASIC Professional Development System 7.1
- Microsoft GW-BASIC 3.2
- Microsoft GW-BASIC 3.22
- Microsoft GW-BASIC 3.23
Retired KB Content DisclaimerThis article was written about products for which Microsoft no longer offers support. Therefore, this article is offered "as is" and will no longer be updated.