ttcompat(7M)
NAME
ttcompat - V7, 4BSD and XENIX STREAMS compatibility module
SYNOPSIS
#define BSD_COMP
#include <sys/stropts.h>
#include <sys/ioctl.h>
ioctl(fd, I_PUSH, "ttcompat");
DESCRIPTION
ttcompat is a STREAMS module that translates the ioctl calls
supported by the older Version 7, 4BSD, and XENIX terminal
drivers into the ioctl calls supported by the termio inter-
face (see termio(7I)). All other messages pass through this
module unchanged; the behavior of read and write calls is
unchanged, as is the behavior of ioctl calls other than the
ones supported by ttcompat.
This module can be automatically pushed onto a stream using
the autopush 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 down-
stream. 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/XENIX 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 sup-
ported. 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/ttold.h> (included 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. If the speed set on the device
is over B38400, then it is reported as B38400 for compati-
bility reasons. If it is set to B38400 and the current
speed is over B38400, the change is ignored. See TIOCGETP
and TIOCSETP below. 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 termi-
nal state, represented by the termios structure.
Delay type 0 (NL0, TAB0, CR0, FF0, BS0) 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 | CR0 (not supported) |
|_______________________|___________________________________|
| TAB1 | TAB1 |
|_______________________|___________________________________|
| TAB2 | TAB2 |
|_______________________|___________________________________|
| XTABS | TAB3 |
|_______________________|___________________________________|
| NL1 | ONLRET|CR1 |
|_______________________|___________________________________|
| NL2 | NL1 |
|_______________________|___________________________________|
| NL3 | NL0 (not supported) |
|_______________________|___________________________________|
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, as follows:
0 (neither EVENP nor ODDP)
Parity is not to be generated on output or checked on
input. The character size is set to CS8 and the
PARENB flag is cleared in the c_cflag field of the
termios structure.
EVENP Even parity characters are to be generated on output
and accepted on input. The INPCK flag is set in the
c_iflag field of the termios structure, the character
size is set to CS7 and the PARENB flag is set in the
c_iflag field of the termios structure.
ODDP Odd parity characters are to be generated on output
and accepted on input. The INPCK flag is set in the
c_iflag, the character size is set to CS7 and the
PARENB and PARODD flags are set in the c_iflag field
of the termios structure.
EVENP|ODDP or ANYP
Even parity characters are to be generated on output
and characters of either parity are to be accepted
on input. The INPCK flag is cleared in the c_iflag
field, the character size is set to CS7 and the PARENB
flag is set in the c_iflag field of the termios struc-
ture.
The RAW flag disables all output processing (the OPOST flag
in the c_oflag field, and the XCASE and IEXTEN flags in the
c_iflag 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). Eight 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_iflag field of the termios structure.
The CRMOD flag turns input carriage return characters into
linefeed characters, and output linefeed characters to be
sent as a carriage 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 charac-
ter 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 gen-
erated 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/ttold.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) */
};
XENIX defines the tchar structure as tc. The characters
are mapped to members of the c_cc field of the termios
structure as follows:
tchars c_cc index
t_intrc VINTR
t_quitc VQUIT
t_startc VSTART
t_stopc VSTOP
t_eofc VEOF
t_brkc VEOL
Also associated with each terminal is a local flag word
(TIOCLSET and TIOCLGET), 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 |
|___________________|_______________________________________|
| LMDMBUF | 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 |
|___________________|_______________________________________|
| LPASS8 | CS8 in the c_cflag 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 |
|___________________|_______________________________________|
Each flag has a corresponding equivalent sg_flags value. The
sg_flags definitions omit the leading "L"; for example,
TIOCSETP with sg_flags set to TOSTOP is equivalent to
TIOCLSET with LTOSTOP.
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 | VSUS |
|___________________|_______________________________________|
| t_dsuspc | VDSUSP |
|___________________|_______________________________________|
| t_rprntc | VREPRINT |
|___________________|_______________________________________|
| t_flushc | VDISCARD |
|___________________|_______________________________________|
| t_werasc | VWERASE |
|___________________|_______________________________________|
| t_lnextc | VLNEXT |
|___________________|_______________________________________|
IOCTLS
ttcompat responds to the following ioctl calls. All others
are passed to the module below.
TIOCGETP
The argument is a pointer to an sgttyb structure. The
current terminal state is fetched; the appropriate
characters in the terminal state are stored in that
structure, as are the input and output speeds. If the
speed is over B38400, then B38400 is returned. The
values of the flags in the sg_flags field are derived
from the flags in the terminal state and stored in the
structure.
TIOCEXCL
Set ``exclusive-use'' mode; no further opens are per-
mitted until the file has been closed.
TIOCNXCL
Turn off ``exclusive-use'' mode.
TIOCSETP
The argument is a pointer to an sgttyb structure. The
appropriate characters and input and output speeds in
the terminal state are set from the values in that
structure, and the flags in the terminal state are set
to match the values of the flags in the 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. If the current device speed
is over B38400 for either input or output speed, and
B38400 is specified through this interface for that
speed, the actual device speed is not changed. If the
device speed is B38400 or lower or if some speed other
than B38400 is specified, then the actual speed speci-
fied is set.
TIOCSETN
The argument is a pointer to an sgttyb structure. The
terminal state is changed as TIOCSETP would change
it, but a TCSETS ioctl is used, so that the interface
neither delays nor discards input.
TIOCHPCL
The argument is ignored. The HUPCL flag is set in the
c_cflag word of the terminal state.
TIOCFLUSH
The argument is a pointer to an int variable. If its
value is zero, all characters waiting in input or out-
put queues are flushed. Otherwise, the value of the
int is treated as the logical OR of the FREAD and
FWRITE flags defined by <sys/file.h>. If the FREAD bit
is set, all characters waiting in input queues are
flushed, and if the FWRITE bit is set, all characters
waiting in output queues are flushed.
TIOCSBRK
The argument is ignored. The break bit is set for the
device. (This is not supported by ttcompat. The
underlying driver must support TIOCSBRK.)
TIOCCBRK
The argument is ignored. The break bit is cleared for
the device. (This is not supported by ttcompat. The
underlying driver must support TIOCCBRK.)
TIOCSDTR
The argument is ignored. The Data Terminal Ready bit
is set for the device.
TIOCCDTR
The argument is ignored. The Data Terminal Ready bit
is cleared for the device.
TIOCSTOP
The argument is ignored. Output is stopped as if the
STOP character had been typed.
TIOCSTART
The argument is ignored. Output is restarted as if the
START character had been typed.
TIOCGETC
The argument is a pointer to a tchars structure. The
current terminal state is fetched, and the appropriate
characters in the terminal state are stored in that
structure.
TIOCSETC
The argument is a pointer to a tchars structure. The
values of the appropriate characters in the terminal
state are set from the characters in that structure.
TIOCLGET
The argument is a pointer to an int. The current ter-
minal state is fetched, and the values of the local
flags are derived from the flags in the terminal state
and stored in the int pointed to by the argument.
TIOCLBIS
The argument is a pointer to an int whose value is a
mask containing flags to be set in the local flags
word. The current terminal state is fetched, and the
values of the local flags are derived from the flags
in the terminal state; the specified flags are set,
and the flags in the terminal state are set to match
the new value of the local flags word.
TIOCLBIC
The argument is a pointer to an int whose value is a
mask containing flags to be cleared in the local flags
word. The current terminal state is fetched, and the
values of the local flags are derived from the flags
in the terminal state; the specified flags are
cleared, and the flags in the terminal state are set
to match the new value of the local flags word.
TIOCLSET
The argument is a pointer to an int containing a new
set of local flags. The flags in the terminal state
are set to match the new value of the local flags
word. (This ioctl was added because sg_flags was once
a 16 bit value. The local modes controlled by
TIOCLSET are equivalent to the modes controlled by
TIOCSETP and sg_flags.)
TIOCGLTC
The argument is a pointer to an ltchars structure. The
values of the appropriate characters in the terminal
state are stored in that structure.
TIOCSLTC
The argument is a pointer to an ltchars structure. The
values of the appropriate characters in the terminal
state are set from the characters in that structure.
FIORDCHK
Returns the number of immediately readable characters.
The argument is ignored. (This ioctl is handled in
the stream head, not in the ttcompat module.)
FIONREAD
Returns the number of immediately readable characters
in the int pointed to by the argument. (This ioctl is
handled in the stream head, not in the ttcompat
module.)
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, and
no message is passed through to the underlying tty driver).
TIOCSETD LDOPEN
TIOCGETD LDCLOSE
DIOCSETP LDCHG
DIOCSETP LDSETT
DIOCGETP LDGETT
The following old ioctls are not supported by ttcompat, but
are supported by Solaris tty drivers. As with all ioctl not
otherwise listed in this documentation, these are passed
through to the underlying driver and are handled there.
TIOCREMOTE
TIOCGWINSZ TIOCSWINSZ
The following ioctls are not supported by ttcompat, and are
generally not supported by Solaris tty drivers. They are
passed through, and the tty drivers return EINVAL.
LDSMAP TIOCNOTTY
LDGMAP TIOCOUTQ
LDNMAP
(Note: LDSMAP, LDGMAP, and LDNMAP are defined in
<sys/termios.h>.)
SEE ALSO
ioctl(2), termios(3C), ldterm(7M), termio(7I)
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