FIX: CodeView Version 4.0 Redirects STDPRN to the Screen

The information in this article applies to:

• Microsoft CodeView for MS-DOS, versions 4.0, 4.01, and 4.05

SYMPTOMS

When version 4.0, 4.01, or 4.05 of CodeView for MS-DOS is used to debug an application that sends output to STDPRN, the output is redirected to the screen.

RESOLUTION

Reopen STDPRN to the PRN device. The sample code below demonstrates the steps involved.

STATUS

Microsoft has confirmed this to be a problem in CodeView versions 4.0, 4.01, and 4.05. This problem was corrected in CodeView version 4.1.

MORE INFORMATION

Sample Code

/* Compile options needed: /Od /Zi (/D_DEBUG to work around problem)
*/

#include <stdio.h>

void main(void)

    fprintf(stdprn, "When running under CV 4.0, this "
                    "is sent to the screen.\n");

    freopen("PRN", "wb", stdprn);

    fprintf(stdprn, "When running under CV 4.0, this "
                    "is sent to the printer.\n");

}