Understanding virtual devices

A number of devices in Interix act as virtual devices; they do not have an implementation in the file system. Examples are nul, serial ports, pseudo terminals, and tape drives. The command ls /dev lists the contents of the virtual device space.

The following table lists and describes these virtual devices:

Virtual device Description
/dev/full A "full" device. Typically used for testing programs. You can always read data from it; write requests fail due to lack of space.
/dev/ntape[09] Tape drives opened in non-rewind mode.
/dev/null The null device.
/dev/proc The process list. Used by ps(1). Also found in /proc.
/dev/ptmx Master pseudo terminal. System V style.
/dev/pty[pz|AE][09|af] Master pseudo terminal. Berkeley style.
/dev/random Random number generator.
/dev/tape[09] Tape drives opened in rewind mode.
/dev/tty[pz|AE][09|af] Subordinate (slave) pseudo terminals.
/dev/tty[0|1][09|af] Serial ports.
/dev/tty The current terminal.
/dev/ttyn[0063] Console terminal windows.
/dev/urandom Random number generator.
/dev/zero A "full" device. Full of zero bytes.

The pseudo terminals are used by different utilities, including xterm(1) and telnet(1). You can have up to 256 pseudo-terminal connections in Interix. A pseudo terminal that is being used by xterm is not available for use in a telnet session.