HOWTO: Use @ ... SAY Commands & Control Codes to Print in FP/W

ID: Q99595

The information in this article applies to:

Microsoft Visual FoxPro for Windows, versions 3.0, 5.0
Microsoft FoxPro for Windows, versions 2.5x, 2.6x

SUMMARY

The following procedures show how to bypass the Windows printer drivers and send control codes directly to the printer for use in combination with @ ... SAY commands.

MORE INFORMATION

FoxPro for Windows cannot send control codes directly to a printer using a Windows printer driver. There are two techniques to work around this:

Open the printer in "raw mode," bypassing the Windows printer driver and communicating directly with the printer.

-or-

Write all output to a text file, then copy the text file to a printer port.

Writing FoxPro for Windows programs that send control codes directly to a printer is not normally recommended. Only use these techniques when adapting existing FoxPro for MS-DOS code that sends control codes to the printer.

The following examples send control codes to switch an Epson FX-80 dot- matrix printer's compressed mode on and off.

NOTE: When using these techniques, do not use any of the ? or ?? commands for output. Only use @ ... SAY commands.

Technique 1: Open the Printer in Raw Mode

There are two ways to open the printer in raw mode:

Use the ??? " " command.

-or-

Use the SET PDSETUP TO <driver name> command.

NOTE: This method will not work under Visual FoxPro unless the FoxPro 2.x file, GENPD.APP, exists. Visual FoxPro does not ship with GENPD.APP, which means that if you want to use GENPD.APP with Visual FoxPro, you must first convert and rebuild it under Visual FoxPro.

Use the ??? " " Command:

Issue SET DEVICE TO PRINT and SET PRINTER TO commands to turn off all open print commands.

Issue a ??? " " command to open the printer in raw mode.

Issue @ ... SAY commands to send control codes and text to the printer.

After printing, issue a SET PRINTER TO command to flush the print buffer and return control to the Windows printer driver.

The following code demonstrates these steps:


   SET DEVICE TO PRINT
   SET PRINTER TO
   ??? " "
   @ 1,0 SAY 'NORMAL TEXT'
   @ 2,0 SAY CHR(15) && Control code to turn compressed mode on
   @ 2,0 SAY 'CONDENSED text?'
   @ 3,0 SAY CHR(18) && Control code to turn compressed mode off
   @ 3,0 SAY 'NORMAL again'
   SET DEVICE TO SCREEN
   SET PRINTER TO

NOTE: In some circumstances, the last @ ... SAY command may not print. If this problem occurs, add an additional @ ... SAY command that prints a blank line (so that the lost line is just a blank). If adding a blank line is not an acceptable workaround, use one of the other methods listed in this article.

Use the SET PDSETUP TO <Driver Name> Command:

NOTE: This method will not work under Visual FoxPro unless the FoxPro 2.x file, GENPD.APP, exists. Visual FoxPro does not ship with GENPD.APP, which means that if you want to use GENPD.APP with Visual FoxPro, you must first convert and rebuild it under Visual FoxPro.

Issue a SET PRINTER TO command to clear the print buffer of all open print commands.

Issue a SET PDSETUP TO <driver name> command to open the printer in raw mode. You MUST already have an existing FoxPro 2.0 or 2.5 for MS-DOS printer driver in the current resource file.

NOTE: The important property of this command is that setting a FoxPro for MS-DOS printer driver opens the printer in raw mode. The printer driver itself is not used to control printing (that is done though control codes). In fact, any FoxPro for MS-DOS printer driver can be used.

Issue a SET DEVICE TO PRINTER command to direct the @ ... SAY commands to the printer.

Issue @ ... SAY commands to send control codes and text to the printer.

After printing, issue a SET DEVICE TO SCREEN command to redirect the output to the screen.

Issue a SET PRINTER TO command to flush the print buffer and return control to the Windows printer driver.

The following code demonstrates these steps:


   SET PRINTER TO
   SET PDSETUP TO "Epson"
   SET DEVICE TO PRINT

   @ 1, 0 SAY 'NORMAL text'
   @ 2, 0 SAY  CHR(15) && Control code to turn compressed mode on
   @ 2, 0 SAY  'CONDENSED text'
   @ 3, 0 SAY  CHR(18) && Control code to turn compressed mode off
   @ 3, 0 SAY 'normal again'

   SET DEVICE TO SCREEN
   SET PRINT TO

Technique 2: Write to Text File and Copy to Printer Port

Issue a SET DEVICE TO FILE <filename> command to direct output to a file.

Issue @ ... SAY commands to send control codes or text to the printer.

Issue a SET DEVICE TO SCREEN command to redirect output to the screen.

Issue a SET SAFETY OFF command so FoxPro for Windows does not confirm copying the output file to the printer port (which it believes to be a file).

Issue a COPY FILE <filename> TO <printer port>.DOS command to copy the output file to the printer port.

Issue a SET SAFETY ON command to turn safety on again.

The following code demonstrates these steps:


   SET DEVICE TO FILE output.prn

   @ 1,0 SAY 'NORMAL text'
   @ 2,0 SAY CHR(15) && Control code to turn compressed mode on
   @ 2,0 SAY 'CONDENSED text'
   @ 3, 0 SAY CHR(18) && Control code to turn compressed mode off
   @ 3, 0 SAY 'Back to normal text'

   SET DEVICE TO SCREEN
   SET SAFETY OFF
   COPY FILE output.prn TO lpt1.dos
   SET SAFETY ON

More Information About Printing to LPT1.DOS: When Windows prints to a file named LPT1.DOS, MS-DOS interprets the request to open the file LPT1.DOS as a request to send data to the printer port, and it sends the data out through its own printing handler. Because Windows thinks that LPT1.DOS is an MS-DOS file, the Print Manager is not used.

For more information about this topic, please see the following articles in the Microsoft Knowledge Base:

Q68652 Printing to Windows LPT1.OS2 or LPT1.DOS Port

Q82749 Using LPT1.OS2, LPT1.DOS, or FILE: Ports When Printing

Additional query words: escape codes sequences native language @...say

Keywords : kbPrinting kbVFp300 kbVFp500
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Issue type : kbhowto