Open Lpt

Open a printer device

Syntax

Open Lpt ["[LPT[x]:][Printer_Name][,TITLE=Doc_Title][,EMU=TTY]"] [For Input|Output] As #filenum

Usage

Open Lpt "LPT..." As [#]filenum or result = Open Lpt( "LPT..." As [#]filenum )

Parameters

x

Specifies a port number. If omitted, output is sent to the system print spooler.

Printer_Name

Name of printer to open. This parameter is ignored on DOS.

TITLE=Doc_Title

Title of the print job as seen by the printer spooler. This parameter is ignored on DOS.

EMU=TTY

Emulation of TTY output on a windows GDI printer, using driver text imaging. This parameter is ignored on DOS and Linux.

For Input|Output

clause is allowed for compatibility, but it is ignored.

filenum

An unused file number to assign to the device.

Return Value

Zero is returned if Open Lpt completed successfully, otherwise a non-zero value is returned to indicate failure.

Description

Open Lpt opens a connection to a printer device. The connection is treated like a file, so data may be written to the printer using Print and Put # commands.

Any printer attached to the system may be opened with Open Lpt

Open Lpt "LPT:" ... will try to open the default printer on Windows and Linux, and "LPT1:" on DOS.

LPrint will automatically try to open the default printer on Windows and Linux, and "LPT1:" on DOS.

Platform specific notes:

Windows

The argument EMU=TTY assumes printable ASCII or Unicode text, and applies printer driver text imaging to the input. EMU=TTY also allows the usage of CR, LF, BS, TAB, FF, etc., for virtual print-head movement...even when the printer is a GDI printer and therefore doesn't itself understand these special characters. If ",EMU=TTY" is omitted, the data must be sent in the printer's language (ESC/P, HPGL, PostScript, etc...). Other useful emulation modes aren't supported yet.

Linux

A printer spooler available through lp must be installed to access printers by name or a default printer. Spooler access was tested only with CUPS, but other spoolers may work that are invoked through lp. Port are zero based on linux. "LPT1:" corresponds with "/dev/lp0".

The data must be sent in the printer's language (ESC/P, HPGL, PostScript, etc...). Emulation modes aren't supported yet.

DOS

FreeBASIC does not support print spoolers on DOS. Printers must be accessible through "LPTx:".

The data must be sent in the printer's language (ESC/P, HPGL, PostScript, etc...). Emulation modes aren't supported yet.

Example

' Send some text to the Windows printer on LPT1:, using driver text imaging. Open Lpt "LPT1:EMU=TTY" For Output As #1 Print #1, "Testing!" Close
' Sends contents of text file test.txt to Windows printer named "ReceiptPrinter" Dim RptInput As String Dim PrintFileNum As Integer, RptFileFileNum As Integer RptFileFileNum = FreeFile Open "test.txt" For Input As #RptFileFileNum PrintFileNum = FreeFile Open Lpt "LPT:ReceiptPrinter,TITLE=ReceiptWinTitle,EMU=TTY" As _ #PrintFilenum While (EOF(RptFileFileNum) = 0) Line Input #RptFileFileNum, RptInput Print #PrintFileNum, RptInput Wend Close #PrintFileNum ' Interestingly, does not require CHR(12). But if pagination is desired, CHR(12) is the way. Close #RptFileFileNum Print "Press any key to end program..." GetKey End

'This simple program will print a PostScript file to a PostScript compatible printer. Dim As UByte FFI, PPO Dim As String temp FFI = FreeFile() Open "sample.ps" For Input Access Read As #FFI PPO = FreeFile() Open Lpt "LPT1:" For Output As #PPO While (EOF(FFI) = 0) Line Input #FFI, temp Print #PPO, temp Wend Close #FFI Close #PPO Print "Printing Completed!"

Dialect Differences

In the -lang qb dialect the old syntax is supported OPEN "LPT:..." . This syntax used in the other dialects will open a regular file.