Open DEVICE File
On Unix-based operating systems, a DEVICE extension file is a special file or useful interface to a device driver that appears on a file system as if it were an ordinary file.
These types of DEVICE files also appear in DOS, OS/2, and Windows.
These DEVICE files allow an application program to interact with a device using its device driver through standard input/output system calls and interrupts.
The use of standard system calls simplifies many programming tasks and leads to consistent I/O mechanisms in user space, regardless of device features and functions.
DEVICE files generally provide simple interfaces to standard devices (such as printers and serial ports), but they can also be used to access specific unique resources on those devices, such as disk partitions.
Additionally, DEVICE files are useful for accessing system resources that have no connection to any actual hardware devices, such as data sinks and random number generators.
There are two general types of DEVICE files in Unix-based operating systems, known as character special files and block special files.
The difference between them lies in the amount of data that the operating system and the hardware read and write.
These together can be called device special files in contrast to named pipes, which aren't attached to a device but aren't ordinary files either.
Software to open a DEVICE file
DEVICE files are binary files that should not be attempted to be opened manually by the user.