What is /dev/ttys# (notice the little s)?

Question

I'm working on linux, trying to get the serial port to work. I know /dev/ttyS0 is a serial port, but what is /dev/ttys0?

Answer 1

see this

For a pseudo terminal pair such as ptyp3 and ttyp3, the pty... is the master or controlling terminal and the tty... is the slave. There are only 16 ttyp's: ttyp0-ttypf (f is a hexadecimal digit). To get more pairs, the 3 letters q, r, s may be used instead of p. For example the pair ttys8, ptys8 is a pseudo terminal pair. The master and slave are really the same "port" but the slave is used by the application program and the master is used by a network program (or the like) which supplies (and gets) data to/from the slave port.

Answer 2

And this: http://lists.opensuse.org/archive/opensuse/2003-12/msg02404.html

Answer 3

In the Linux devices.txt file in the kernel docs it says:

3 char    Pseudo-TTY slaves
      0 = /dev/ttyp0    First PTY slave
      1 = /dev/ttyp1    Second PTY slave
        ...
    255 = /dev/ttyef    256th PTY slave

    These are the old-style (BSD) PTY devices; Unix98
    devices are on major 136 and above.

and goes on to say

4 char    TTY devices
      0 = /dev/tty0     Current virtual console

      1 = /dev/tty1     First virtual console
        ...
     63 = /dev/tty63    63rd virtual console
     64 = /dev/ttyS0    First UART serial port
        ...
    255 = /dev/ttyS191  192nd UART serial port

    UART serial ports refer to 8250/16450/16550 series devices.

    Older versions of the Linux kernel used this major
    number for BSD PTY devices.  As of Linux 2.1.115, this
    is no longer supported.  Use major numbers 2 and 3.

I don't know how much this helps you, but should get you started in the right direction.