Physical Devices (Windows*)

This topic only applies to Windows* operating systems.

I/O statements that do not refer to a specific file or I/O device read from standard input and write to standard output. Standard input is the keyboard, and standard output is the screen (console). To perform input and output on a physical device other than the keyboard or screen, you specify the device name as the filename to be read from or written to.

Some physical device names are determined by the host operating system; others are recognized by Intel Fortran. Extensions on most device names are ignored.

Filenames for Device I/O
Device	Description
CON	Console (standard output)
PRN	Printer
COM1	Serial port #1
COM2	Serial port #2
COM3	Serial port #3
COM4	Serial port #4
LPT1	Parallel Port #1
LPT2	Parallel Port #2
LPT3	Parallel Port #3
LPT4	Parallel Port #4
NUL	NULL device. Discards all output; contains no input
AUX	Serial port #1
LINE	Serial port #1
USER	Standard output
ERR	Standard error
CONOUT$	Standard output
CONIN$	Standard input

Note

If you use the LINE, USER, or ERR name with an extension, for example, LINE.TXT, Fortran will write to a file rather than to the device.

Examples of opening physical devices as units are:

  OPEN (UNIT = 4, FILE = 'PRN')
  OPEN (UNIT = 7, FILE = 'LPT2', ERR = 100)