tty.4

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 4 代码 · 共 1,190 行 · 第 1/3 页

B150	5	150 baud
B200	6	200 baud
B300	7	300 baud
B600	8	600 baud
B1200	9	1200 baud
B1800	10	1800 baud
B2400	11	2400 baud
B4800	12	4800 baud
B9600	13	9600 baud
EXTA	14	External A (19200 baud)
EXTB	15	External B (38400 baud)
.fi
.DT
.PP
Code conversion and line control required for
IBM 2741s (134.5 baud)
must be implemented by the user's
program.
The half-duplex line discipline
required for the 202 dataset (1200 baud)
is not supplied; full-duplex 212 datasets work fine.
.PP
The
.I sg_erase
and
.I sg_kill
fields of the argument structure
specify the erase and kill characters respectively.
(Defaults are the number sign (#) and the at sign (@).)
.PP
The
.I sg_flags
field of the argument structure
contains several bits that determine the
system's treatment of the terminal:
.NXR "sgttyb file" "sg_flags field contents"
.PP
.ta \w'ALLDELAY 'u +\w'0100000 'u
.nf
ALLDELAY	0177400	Delay algorithm selection
.sp
BSDELAY	0100000	Select backspace delays (not implemented):
BS0	0
BS1	0100000
.sp
VTDELAY	0040000	Select form-feed and vertical-tab delays:
FF0	0
FF1	0100000
.sp
CRDELAY	0030000	Select carriage-return delays:
CR0	0
CR1	0010000
CR2	0020000
CR3	0030000
.sp
TBDELAY	0006000	Select tab delays:
TAB0	0
TAB1	0002000
TAB2	0004000
XTABS	0006000
.sp
NLDELAY	0001400	Select new-line delays:
NL0	0
NL1	0000400
NL2	0001000
NL3	0001400
.sp
EVENP	0000200	Even parity allowed on input (most terminals)
ODDP	0000100	Odd parity allowed on input
RAW	0000040	Raw mode: wake up on all characters, 8-bit interface
CRMOD	0000020	Map CR into LF; echo LF or CR as CR-LF
ECHO	0000010	Echo (full duplex)
LCASE	0000004	Map uppercase to lowercase on input
CBREAK	0000002	Return each character as soon as typed
TANDEM	0000001	Automatic flow control
.DT
.fi
.PP
The delay bits specify how long
transmission stops to allow for mechanical or other movement,
when certain characters are sent to the terminal.
In all cases, a value of 0 indicates no delay.
.PP
Backspace delays are ignored but might
be used for Terminet 300s.
.PP
If a form-feed/vertical tab delay is specified,
it lasts for about two seconds.
.PP
Carriage-return delay type 1 lasts about .08 seconds
and is suitable for the Terminet 300.
Delay type 2 lasts about .16 seconds and is suitable
for the VT05 and the TI 700.
Delay type 3 is suitable for the Concept-100 and pads lines
to be at least nine characters at 9600 baud.
.PP
New-line delay type 1 is dependent on the current column
and is tuned for Teletype Model 37s.
Type 2 is useful for the VT05 and is about .10 seconds.
Type 3 is is 0 and is unimplemented.
.PP
Tab delay type 1 is dependent on the amount of movement
and is tuned to the Teletype Model
37.
Type 3, called XTABS,
is not a delay at all but causes tabs to be replaced
by the appropriate number of spaces on output.
.PP
The flags for even and odd parity control parity checking on input and
generation on output in cooked and CBREAK mode.  
Even parity is generated on
output unless ODDP is set and EVENP is clear,
in which case odd parity is
generated.  For no parity, set both ODDP and EVENP flags.
Input characters with the wrong parity, as determined by EVENP and
ODDP, are ignored in cooked and CBREAK mode.
.PP
RAW
disables all processing save output flushing with LFLUSHO;
full eight bits of input are given as soon as
it is available; all eight bits are passed on output.
A break condition in the input is reported as a null character.
If the input queue overflows in raw mode, it is discarded; this applies
to both new and old drivers.
.PP
CRMOD causes input carriage returns to be turned into
newlines;
input of either CR or LF causes LF-CR both to
be echoed
(for terminals with a newline function).
.PP
CBREAK is a sort of half-cooked mode.
Programs can read each character as soon as typed, instead
of waiting for a full line;
all processing is done, except the input editing:
character and word erase and line kill, input reprint,
and the special treatment of the backslash (\e) or EOT are disabled.
.PP
TANDEM mode causes the system to produce
a stop character (default, CTRL/S), whenever the input
queue is in danger of overflowing, and a start character
(default CTRL/Q),
when the input queue has drained sufficiently.
It is useful for flow control when the ``terminal''
is really another computer that understands the conventions.
.PP
.B Basic ioctls \- 
In addition to the TIOCSETD and TIOCGETD disciplines discussed
in \fBLine disciplines\fR,
a large number of other
.MS ioctl 2
calls apply to terminals and have the general form:
.PP
.B #include <sgtty.h>
.PP
.B ioctl(fildes, code, arg)
.br
.B struct sgttyb *arg;
.PP
The applicable codes are:
.NXR "terminal interface" "general ioctl calls"
.IP TIOCGETP 15
Fetch the basic parameters associated with the terminal and store
in the pointed-to \fIsgttyb\fR structure.
.IP TIOCSETP
Set the parameters according to the pointed-to \fIsgttyb\fR structure.
The interface delays until output is quiescent,
and then throws away any unread characters,
before changing the modes.
.IP TIOCSETN
Set the parameters like TIOCSETP but do not delay or flush input.
Input is not preserved, however, when changing to or from RAW.
.PP
With the following codes the
.I arg
is ignored.
.IP TIOCEXCL 15
Set \*(lqexclusive-use\*(rq mode:
all open calls to this line have been closed. This setting does not prevent
superuser opens of the terminal line. 
.IP TIOCNXCL
Turn off \*(lqexclusive-use\*(rq mode.
.IP TIOCHPCL
When the file is closed for the last time,
hang up the terminal.
This is useful when the line is associated
with an ACU used to place outgoing calls.
.PP
Setting the pointed-to integer parameter to the following values
determines how TIOCFLUSH functions.
.IP TIOCFLUSH 15
FREAD flushes input queues.
FWRITE flushes output queues. Zero (0) flushes both.
FREAD and FWRITE are defined in 
.PN <sys/file.h> .
.PP
In cases where arguments are required, they are described; \fIarg\fR
should otherwise be given as zero (0).
.IP TIOCSTI 15
The argument is the address of a character that the system
pretends was typed on the terminal.
.IP TIOCSBRK 15
The break bit is set in the terminal.
.IP TIOCCBRK
The break bit is cleared.
.IP TIOCSDTR 
Data terminal ready is set.
.IP TIOCCDTR
Data terminal ready is cleared.
.IP TIOCSTOP
Output is stopped, as if the ``stop'' character had been typed.
.IP TIOCSTART
Output is restarted, as if the ``start'' character had been typed.
.IP TIOCGPGRP
.I arg 
is the address of a word into which is placed the process group
number of the control terminal.
.IP TIOCSPGRP
.I arg 
is a word (typically a process ID) that becomes the process
group for the control terminal.
.IP FIONREAD
Returns in the long integer whose address is 
.I arg, 
the number
of immediately readable characters from the argument unit.
.PP
.B Tchars \- 
The second structure associated with each terminal specifies
characters that are special in both the old and new terminal interfaces.
The following structure is defined in 
.PN <sys/ioctl.h> ,
which is automatically included in 
.PN <sgtty.h> :
.PP
.EX
struct tchars {
        char    t_intrc;    /* interrupt */
        char    t_quitc;    /* quit */
        char    t_startc;   /* start output */
        char    t_stopc;    /* stop output */
        char    t_eofc;	    /* end-of-file */
        char    t_brkc;     /* input delimiter (like nl) */
};
.EE
.PP
The default values for these characters are
CTRL/?, CTRL/\e\|, CTRL/Q, CTRL/S, CTRL/D, and \-1.
A character value of \-1
eliminates the effect of that character.
The
.I t_brkc
character, by default \-1,
acts like a newline in that it terminates a ``line'',
is echoed, and is passed to the program.
The ``stop'' and \*Qstart\*U characters may be the same,
to produce a toggle effect.
It is probably counterproductive to make
other special characters (including erase and kill)
identical.
The applicable ioctl calls are:
.IP TIOCGETC 12
Get the special characters and put them in the specified structure.
.IP TIOCSETC 12
Set the special characters to those given in the structure.
.PP
.B Local mode \- 
.NXR "terminal interface" "local mode word"
The third structure associated with each terminal is a local mode word.
The bits of the local mode word are:
.sp
.nf
LCRTBS	0x0001	Backspace on erase, rather than echoing erase
LPRTERA	0x0002	Printing terminal erase mode
LCRTERA	0x0004	Erase character echoes as backspace-space-backspace
LTILDE	0x0008	Convert ~ to \` on output (for Hazeltine terminals)
LLITOUT	0x0020	Suppress output translations
LTOSTOP	0x0040	Send SIGTTOU for background output
LFLUSHO	0x0080	Output is being flushed
LNOHANG	0x0100	Do not send hangup when carrier drops
LAUTOFLOW	0x0200	Hardware responds to flow control characters. (See \fBFlow control\fP.)
LCRTKIL	0x0400	BS-space-BS erase entire line on line kill
LPASS8	0x0800	Allow 8-bit characters in input and output
LCTLECH	0x1000	Echo input control chars as ^X, delete as ^?
LPENDIN	0x2000	Retype pending input at next read or input character
LDECCTQ	0x4000	Only CTRL/Q restarts output after CTRL/S
LNOFLSH	0x8000	Do not flush output on receipt of suspend or interrupt character
.fi
.sp
The applicable
.PN ioctl
functions are:
.IP TIOCLBIS 15
.I arg 
is the address of a 
mask of bits to be set in the local mode word.
.IP TIOCLBIC
.I arg 
is the address of a mask of
bits to be cleared in the local mode word.
.IP TIOCLSET
.I arg 
is the address of a mask to be placed in the local mode word.
.IP TIOCLGET
.I arg 
is the address of a word into which the current mask is placed.
.PP
.B Window Size \-  
The fourth structure associated with terminals is the 
.PN winsize
structure that defines the size of the terminal window.
The
.PN winsize
structure is defined as follows:
.EX
struct winsize {
        unsigned short  ws_row, ws_col;         
        unsigned short  ws_xpixel, ws_ypixel;  
};
.EE
The 
.I ws_row 
and 
.I ws_col 
elements define the window size in terms of the number
of characters per row and column respectively.  The 
.I ws_xpixel 
and 
.I ws_ypixel
define the window size in terms of pixels.  The default value is to initialize
each of the elements to zero.
.sp
The applicable
.PN ioctl
functions are:
.IP TIOCSWINSZ 15
.I arg 
is the address of a
.PN winsize
structure, which defines the new window sizes.  This will send a SIGWINCH
signal to notify all members of process group that the window size has changed.
.IP TIOCGWINSZ 15
.I arg 
is the address of a
.PN winsize
structure into which is placed
the current window size settings.
.PP
.B Local special characters \-  
.NXR "terminal interface" "local special characters"
The
final structure associated with each terminal is the
.PN ltchars
structure that defines interrupt characters
for the new terminal driver.
Its structure is:
.EX
struct ltchars {
        char    t_suspc;      /* stop process signal */
        char    t_dsuspc;     /* delayed stop process signal */
        char    t_rprntc;     /* reprint line */
        char    t_flushc;     /* flush output (toggles) */
        char    t_werasc;     /* word erase */
        char    t_lnextc;     /* literal next character */
};
.EE
.PP
The default values for these characters are CTRL/Z, CTRL/Y, CTRL/R, CTRL/O, 
CTRL/W, and CTRL/V.
A value of \-1 disables the character.
.PP
The applicable ioctl functions are:
.IP TIOCSLTC 12
.I args 
is the address of an
.PN ltchars
structure, which defines the new local special characters.
.IP TIOCGLTC 12
.I args 
is the address of an
.PN ltchars
structure, into which is placed
the current set of local special characters.
.SH Restrictions
.NXR "terminal interface" "restricted"
Half-duplex terminals are not supported.
.SH Files
.PN /dev/tty
.br
.PN /dev/tty*
.br
.PN /dev/console
.SH See Also
csh(1), stty(1), tset(1), ioctl(2), sigvec(2), stty(3), 
termio(4), termios(4), getty(8), MAKEDEV(8)