PRB: SYS(6) Function Returns Empty String

ID: Q156867

The information in this article applies to:

Microsoft Visual FoxPro for Windows, versions 5.0, 6.0

SYMPTOMS

The SYS(6) function returns an empty string in Visual FoxPro 5.0. In earlier versions of FoxPro, the function returned information on the current printer port or "PRN."

WORKAROUND

No Visual FoxPro command exists that returns the current printer port. Some Application Program Interface (API) calls exist that return information that might be useful. See the FoxPro Help file and search on the keyword API.

STATUS

This behavior is by design.

MORE INFORMATION

In FoxPro for MS-DOS, the SYS(6) function returns the port that FoxPro uses for printing. Under FoxPro for Windows 2.x and Visual FoxPro 3.0, the SYS(6) function returns "PRN" regardless of the port (if any) the driver is using. However, this is potentially misleading under Windows. PRN generally means the port LPT1. Windows allows a printer driver to direct its output to a variety of ports. Therefore, returning "PRN" does not tell you which port holds the printer driver connection.

Under Visual FoxPro 5.0, the SYS(6) function does return useful information if the printer is redirected to a file. For example, if the printer is set to a particular file, the SYS(6) function returns the MS-DOS path and file name of the destination file.

In conclusion, do not use the SYS(6) function to return the printer port of a Windows printer driver. Use SYS(6) to determine if a printer is currently redirected to a file.

Steps to Reproduce Behavior

In the Command window, type the following lines of code:


   x=SYS(6)
   DISPLAY MEMORY LIKE x
   SET PRINTER TO Test.txt
   ? SYS(6)

The variable x contains an empty string when initially set to SYS(6). After redirecting the printer to a file, the SYS(6) function returns the path and file name of Test.txt.

Additional query words: VFoxWin kbdsd

Keywords : kbVFp500 kbVFp600 FxprgGeneral
Version : WINDOWS:5.0,6.0
Platform : WINDOWS
Issue type :