Output device

As output devices, all devices are referred to in the computer technology, make available the result of an operation or a program of the outside world. These are in particular:

• Screen / projector for volatile visible output,
• Printer / plotter for permanent visual output,
• Speaker / headset for audible output,
• Braille for tactile output.

In conjunction with an input device interaction is possible with a computer program.

Zero unit

The null device (including zero device ) is a virtual output device. It is used under different operating systems. It serves to suppress mainly in batch files expenditure of a command. The output will be redirected to this effect to the device.

On Windows / MS -DOS, it is the device Nul:

On Linux and UNIX, it is / dev / null

The AmigaDOS Nile.

Example of the application under MS- DOS:

Path c: \ dos > nul If the directory c: \ dos exist, so it is included in the search path. It does not exist, this also does not happen. In any case, a ( ugly and unprofessional acting ) error message is not on the screen, but to nul: sent, not shown.