ttcompat(7) DG/UX 5.4.2 ttcompat(7)
NAME
ttcompat - V7, 4BSD and XENIX STREAMS compatibility module
SYNOPSIS
#include <sys/stream.h>
#include <sys/stropt.h>
#include <sys/ttcompat.h>
#include <sys/ttold.h>
ioctl(fd, IPUSH, "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 interface [see
termio(7)]. 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 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/XENIX functions may not be supported. For
example, if the CBAUD bits in the ccflag field are not supported,
the functions provided by the sgispeed and sgospeed 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 sgispeed;
char sgospeed;
char sgerase;
char sgkill;
int sgflags;
};
The sgispeed and sgospeed fields describe the input and output
speeds of the device, and reflect the values in the ccflag field of
the termios structure. The sgerase and sgkill fields of the
argument structure specify the erase and kill characters
respectively, and reflect the values in the VERASE and VKILL members
of the ccc field of the termios structure.
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The sgflags 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
coflag field of the termios structure. Other delay mappings are
performed as follows:
sgflags coflag
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 ciflag 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:
Parity is not to be generated on output or checked on input;
the character size is set to CS8 and the flag is cleared in the
ccflag field of the termios structure.
Even parity characters are to be generated on output and accepted on
input;
the flag is set in the ciflag field of the termios structure, the
character size is set to CS7 and the flag is set in the ccflag
field of the termios structure.
Odd parity characters are to be generated on output and accepted on
input; the flag is set in the
ciflag field, the character size is set to CS7 and the and flags
are set in the ccflag field of the termios structure.
Even parity characters are to be generated on output and characters
of either parity are to be accepted on input;
the flag is cleared in the ciflag field, the character size is set
to CS7 and the flag is set in the ccflag field of the termios
structure.
The RAW flag disables all output processing (the OPOST flag in the
coflag field, and the XCASE flag in the clflag field, are cleared
in the termios structure) and input processing (all flags in the
ciflag 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
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and the PARENB and PARODD flags are cleared in the ccflag field of
the termios structure. The signal-generating and line-editing
control characters are disabled by clearing the ISIG and ICANON flags
in the clflag 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 ciflag field, and the
OPOST and ONLCR flags in the coflag 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
ciflag 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 coflag 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 clflag field).
Other flags are directly mapped to flags in the termios structure:
sgflags flags in termios structure
CBREAK complement of ICANON in clflag field
ECHO ECHO in clflag field
TANDEM IXOFF in ciflag 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 tintrc; /* interrupt */
char tquitc; /* quit */
char tstartc; /* start output */
char tstopc; /* stop output */
char teofc; /* end-of-file */
char tbrkc; /* input delimiter (like nl) */
};
XENIX defines the tchar structure as tc. The characters are mapped
to members of the ccc field of the termios structure as follows:
tchars ccc index
tintrc VINTR
tquitc VQUIT
tstartc VSTART
tstopc VSTOP
teofc VEOF
tbrkc VEOL
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:
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local flags flags in termios structure
LCRTBS not supported
LPRTERA ECHOPRT in the clflag field
LCRTERA ECHOE in the clflag field
LTILDE not supported
LTOSTOP TOSTOP in the clflag field
LFLUSHO FLUSHO in the clflag field
LNOHANG CLOCAL in the ccflag field
LCRTKIL ECHOKE in the clflag field
LCTLECH CTLECH in the clflag field
LPENDIN PENDIN in the clflag field
LDECCTQ complement of IXANY in the ciflag field
LNOFLSH NOFLSH in the clflag 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 tsuspc; /* stop process signal */
char tdsuspc; /* delayed stop process signal */
char trprntc; /* reprint line */
char tflushc; /* flush output (toggles) */
char twerasc; /* word erase */
char tlnextc; /* literal next character */
};
The characters are mapped to members of the ccc field of the termios
structure as follows:
ltchars ccc index
tsuspc VSUSP
tdsuspc VDSUSP
trprntc VREPRINT
tflushc VDISCARD
twerasc VWERASE
tlnextc 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. The
values of the flags in the sgflags field are derived
from the flags in the terminal state and stored in the
structure.
TIOCEXCL Set ``exclusive-use'' mode; no further opens are
permitted until the file has been closed.
TIOCNXCL Turn off ``exclusive-use'' mode.
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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 sgflags 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.
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
ccflag 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 output
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.
TIOCBRK The argument is ignored. The break bit is set for the
device.
TIOCCBRK The argument is ignored. The break bit is cleared for
the device.
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.
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TIOCLGET The argument is a pointer to an int. The current
terminal 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.
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 FIORDCHK returns the number of immediately readable
characters. The argument is ignored.
FIONREAD FIONREAD returns the number of immediately readable
characters in the int pointed to by the argument.
LDSMAP Calls the function emsetmap (tp, mp) if the function is
configured in the kernel.
LDGMAP Calls the function emgetmap (tp, mp) if the function is
configured in the kernel.
LDNMAP Calls the function emunmap (tp, mp) if the function is
configured in the kernel.
The following ioctls are returned as successful for the sake of
compatibility. However, nothing significant is done (i.e., the state
of the terminal is not changed in any way).
TIOCSETD LDOPEN
TIOCGETD LDCLOSE
DIOCSETP LDCHG
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DIOCSETP LDSETT
DIIOGETP LDGETT
SEE ALSO
ioctl(2), termios(2), termio(7), ldterm(7).
NOTES
TIOCBRK and TIOCCBRK should be handled by the driver. FIONREAD and
FIORDCHK are handled in the stream head.
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