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#include <sys/stream.h> #include <sys/stropts.h> #include <sys/ttold.h>ioctl(fd, I_PUSH, "ttcompat");
This module can be automatically pushed onto a stream
with the
autopush(1M)
mechanism when a terminal device is opened; it does not have to be explicitly
pushed onto a stream.
This module requires that the
termios
interface be supported by the modules and the application can push
the driver downstream.
The
TCGETS, TCSETS, and
TCSETSF ioctl calls
must be supported; if any information set or fetched by those
ioctl calls is not supported by the modules and driver downstream,
some of the V7/4BSD functions may not be supported.
For example, if the
CBAUD bits in the c_cflag
field are not supported, the functions provided by the
sg_ispeed
and sg_ospeed
fields of the sgttyb
structure (see below) will not be supported.
If the TCFLSH ioctl
is not supported, the function provided by the
TIOCFLUSH ioctl
will not be supported.
If the
TCXONC ioctl
is not supported, the functions provided by the
TIOCSTOP
and
TIOCSTART
ioctl
calls
will not be supported.
If the
TIOCMBIS
and
TIOCMBIC
ioctl
calls
are not supported, the functions provided by the
TIOCSDTR
and
TIOCCDTR
ioctl
calls
will not be supported.
The basic ioctl calls use the sgttyb structure defined by sys/ioctl.h:
struct sgttyb { char sg_ispeed; char sg_ospeed; char sg_erase; char sg_kill; int sg_flags; };
The
sg_ispeed
and
sg_ospeed
fields describe the input and output speeds of the
device, and reflect the values in the
c_cflag
field of the
termios
structure.
The
sg_erase
and
sg_kill
fields of the argument structure
specify the erase and kill characters respectively, and reflect the
values in the
VERASE
and
VKILL
members of the
c_cc
field of the
termios
structure.
The
sg_flags
field of the argument structure
contains several flags that determine the
system's treatment of the terminal.
They are mapped into flags in
fields of the terminal state, represented by the
termios
structure.
Delay type 0 is always mapped into the equivalent delay type 0 in the
c_oflag
field of the termios
structure.
Other delay mappings are performed as follows:
sg_flags | c_oflag |
---|---|
BS1 | BS1 |
FF1 | VT1 |
CR1 | CR2 |
CR2 | CR3 |
CR3 | Not supported |
TAB1 | TAB1 |
TAB2 | TAB2 |
XTABS | TAB3 |
NL1 | ONLRET|CR1 |
NL2 | NL1 |
If previous TIOCLSET or
TIOCLBIS ioctl calls
have not selected LITOUT
or
PASS8 mode, and if RAW
mode is not selected, the
ISTRIP flag is set in the
c_iflag
field of the
termios structure, and the
EVENP and ODDP
flags control the parity of characters sent to the terminal and
accepted from the terminal:
The character size is set to
CS8 and the flag is cleared in the
c_cflag
field of the
termios
structure.
The flag is set in the
c_iflag
field of the
termios
structure, the character size is set to
CS7
and the
flag is set in the
c_cflag
field of the
termios
structure.
The flag is set in the
c_iflag
field, the character size is set to
CS7
and the and flags are set in the
c_cflag
field of the
termios
structure.
The flag is cleared in the
c_iflag
field, the character size is set to
CS7
and the
flag is set in the
c_cflag
field of the
termios
structure.
c_oflag
field, and the XCASE flag in the
c_lflag
field, are cleared in the
termios
structure) and input processing (all flags in the
c_iflag
field other than the
IXOFF and
IXANY
flags are cleared in the
termios
structure).
8 bits of data, with no parity bit,
are accepted on input and generated on output; the character size is
set to
CS8
and the
PARENB
and
PARODD
flags are cleared in the
c_cflag
field of the
termios
structure.
The signal-generating and line-editing control characters are
disabled by clearing the
ISIG and ICANON
flags in the
c_lflag
field of the
termios
structure.
The
CRMOD
flag turns input
<Return>
characters into
newline
characters, and output and echoed
newline
characters to be output as a
<Return>
followed by a
linefeed.
The
ICRNL
flag in the
c_iflag
field, and the
OPOST
and
ONLCR
flags in the
c_oflag
field, are set in the
termios
structure.
The
LCASE
flag maps upper-case letters in the
ASCII
character set to their lower-case equivalents on input (the
IUCLC
flag is set in the
c_iflag
field), and maps lower-case letters in the
ASCII
character set to their upper-case equivalents on output (the
OLCUC
flag is set in the
c_oflag
field).
Escape sequences are accepted on input, and generated on
output, to handle certain
ASCII
characters not supported by older terminals (the
XCASE
flag is set in the
c_lflag
field).
Other flags are directly mapped to flags in the termios structure:
sg_flags | Flags in termios structure |
---|---|
CBREAK |
Complement of ICANON in c_lflag field
|
ECHO |
ECHO in c_lflag field
|
TANDEM |
IXOFF in c_iflag field
|
Another structure associated with each terminal specifies characters that are special in both the old Version 7 and the newer 4BSD terminal interfaces. The following structure is defined by sys/ioctl.h:
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) */ };
Also associated with each terminal is a local flag
word, specifying flags supported by the new 4BSD
terminal interface.
Most of these flags are directly mapped to flags in the
termios
structure:
Local flags | Flags in termios structure |
---|---|
LCRTBS | Not supported |
LPRTERA |
ECHOPRT in the c_lflag field
|
LCRTERA |
ECHOE in the c_lflag field
|
LTILDE | Not supported |
LTOSTOP |
TOSTOP in the c_lflag field
|
LFLUSHO |
FLUSHO in the c_lflag field
|
LNOHANG |
CLOCAL in the c_cflag field
|
LCRTKIL |
ECHOKE in the c_lflag field
|
LCTLECH |
CTLECH in the c_lflag field
|
LPENDIN |
PENDIN in the c_lflag field
|
LDECCTQ |
Complement of IXANY in the c_iflag field
|
LNOFLSH |
NOFLSH in the c_lflag field
|
Another structure associated with each terminal is the ltchars structure which defines control characters for the new 4BSD terminal interface. Its structure is:
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 */ };
The characters are mapped to members of the
c_cc
field of the
termios
structure as follows:
ltchars | c_cc index |
---|---|
t_suspc
| VSUSP |
t_dsuspc
| VDSUSP |
t_rprntc
| VREPRINT |
t_flushc
| VDISCARD |
t_werasc
| VWERASE |
t_lnextc
| VLNEXT |
sg_flags
field are derived from the flags in the terminal state and stored in
the structure.
sg_flags
field of that structure.
The state is changed with a
TCSETSF
ioctl
so that the interface delays until output is quiescent,
then throws away any unread characters, before changing the modes.
c_cflag
word of the terminal state.
The following ioctls are returned as successful for the sake of compatibility. However, nothing significant is done (that is, the state of the terminal is not changed in any way).
TIOCSETD | LDOPEN |
TIOCGETD | LDCLOSE |
DIOCSETP | LDCHG |
DIOCSETP | LDSETT |
DIIOGETP | LDGETT |