NAME

pty − pseudo terminal driver

SYNOPSIS

pseudo-device pty

DESCRIPTION

The pty driver provides support for a device-pair termed a pseudo terminal. A pseudo terminal is a pair of character devices, a master device and a slave device.  The slave device provides processes an interface identical to that described in tty(4). However, whereas all other devices which provide the interface described in tty(4) have a hardware device of some sort behind them, the slave device has, instead, another process manipulating it through the master half of the pseudo terminal. That is, anything written on the master device is given to the slave device as input and anything written on the slave device is presented as input on the master device.

In configuring, if no optional “count” is given in the specification, 16 pseudo terminal pairs are configured. 

The following ioctl calls apply only to pseudo terminals:

TIOCSTOP
Stops output to a terminal (e.g. like typing ^S).  Takes no parameter.

TIOCSTART
Restarts output (stopped by TIOCSTOP or by typing ^S). Takes no parameter.

TIOCPKT
Enable/disable packet mode.  Packet mode is enabled by specifying (by reference) a nonzero parameter and disabled by specifying (by reference) a zero parameter.  When applied to the master side of a pseudo terminal, each subsequent read from the terminal will return data written on the slave part of the pseudo terminal preceded by a zero byte (symbolically defined as TIOCPKT_DATA), or a single byte reflecting control status information.  In the latter case, the byte is an inclusive-or of zero or more of the bits:

TIOCPKT_FLUSHREAD
whenever the read queue for the terminal is flushed.

TIOCPKT_FLUSHWRITE
whenever the write queue for the terminal is flushed.

TIOCPKT_STOP
whenever output to the terminal is stopped a la ^S.

TIOCPKT_START
whenever output to the terminal is restarted.

TIOCPKT_DOSTOP
whenever t_stopc is ^S and t_startc is ^Q. 

TIOCPKT_NOSTOP
whenever the start and stop characters are not ^S/^Q.

This mode is used by rlogin(1C) and rlogind(8C) to implement a remote-echoed, locally ^S/^Q flow-controlled remote login with proper back-flushing of output; it can be used by other similar programs.

TIOCREMOTE
A mode for the master half of a pseudo terminal, independent of TIOCPKT.  This mode causes input to the pseudo terminal to be flow controlled and not input edited (regardless of the

NAME

hp − disk interface

SYNOPSIS

HP0 at address 0x3ffdc0/17776700

DESCRIPTION

Files with minor device numbers 0 through 7 refer to various portions of drive 0; minor devices 8 through 15 refer to drive 1, etc.  The standard device names begin with “hp” followed by the drive number and then a letter a-h for partitions 0-7 respectively.  The character ? stands here for a drive number in the range 0-7. 

The block file’s access the disk via the system’s normnal mode).  Each write to the control term

4th Berkeley Distribution  —  1 August 1985