This article presents three methods an application can use to send output to a printer.

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Method 1

The first method uses the fprintf() function with the preopened "stdprn" stream. The following code example demonstrates this technique:

   #include <stdio.h>
   main()
   {
      fprintf(stdprn, "a line of text\n");
   }
				

This method works only in the MS-DOS operating system because the "stdprn" stream is not defined by Microsoft Windows or Microsoft Windows NT.

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Method 2

Another method uses the fopen() function to open the LPT1, LPT2, or PRN device as a file and uses the fprintf() function to write data to the file handle returned by fopen(). The following code example demonstrates this technique:

   #include <stdio.h>
   main()
   {
      FILE *stream;

      stream = fopen("PRN", "w");
      fprintf(stream, "a line of text\n");
   }
				

This method works in Windows NT as well as the MS-DOS and Windows operating systems.

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Method 3

Finally, in MS-DOS, an application can use the int86() or int86x() functions to call one of the following BIOS printer services provided by Interrupt 17h:

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For more information on the int86() and int86x() functions, refer to the Microsoft C "Run-Time Library Reference" manual.

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