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TTY(4)                  COMMAND REFERENCE                  TTY(4)



NAME
     tty - general terminal interface for 6130 System
     workstations

SYNOPSIS
     #include <sgtty.h>

DESCRIPTION
     NOTE:  This tty interface might change in future releases.

     This section describes both a particular special file
     /dev/tty and the terminal drivers used for conversational
     computing.


     Line disciplines.

     The system provides different line disciplines for
     controlling communications lines.  In this version of the
     system there are three disciplines available:

     old     The old (standard) terminal driver.  This is used
             when using the standard shell sh(1sh) and for
             compatibility with other standard version 7 UNIX
             systems.

     new     A newer terminal driver, with features for job
             control; this must be used when using csh(1csh).

     Line discipline switching is accomplished with the TIOCSETD
     ioctl:

          int ldisc = LDISC; ioctl(fd, TIOCSETD, &ldisc);

     where LDISC is OTTYDISC for the standard tty driver,
     NTTYDISC for the new driver and NETLDISC for the networking
     discipline.  The standard (currently old) tty driver is
     discipline 0 by convention.  The current line discipline can
     be obtained with the TIOCGETD ioctl.  Pending input is
     discarded when the line discipline is changed.

     All of the low-speed asynchronous communications ports can
     use any of the available line disciplines, no matter what
     hardware is involved.  The remainder of this section
     discusses the "old" and "new" disciplines.


     The control terminal.

     When a terminal file is opened, it causes the process to
     wait until a connection is established.  In practice, user
     programs seldom open these files; they are opened by init(8)



Printed 10/17/86                                                1





TTY(4)                  COMMAND REFERENCE                  TTY(4)



     and become a user's standard input and output file.

     If a process which has no control terminal opens a terminal
     file, then that terminal file becomes the control terminal
     for that process.  The control terminal is thereafter
     inherited by a child process during a fork(2), even if the
     control terminal is closed.

     The file /dev/tty is, in each process, a synonym for a
     control terminal associated with that process.  It is useful
     for programs that wish to be sure of writing messages on the
     terminal no matter how output has been redirected.  It can
     also be used for programs that demand a file name for
     output, when typed output is desired and it is tiresome to
     find out which terminal is currently in use.

     The association between a process and its control terminal
     can be broken by the TIOCNOTTY ioctl(2).  TIOCNOTTY does not
     close any existing file descriptors.  Therefore, you can
     place the ioctl and still read and write from the file.  But
     you no longer have a control terminal.  Note that TIOCNOTTY
     has no effect if the tty you apply it to is not the control
     terminal.

     A common use of TIOCNOTTY follows:

          if((fd = open ("/dev/tty",O_WRONLY)) >= 0){
                 ioctl (fd, TIOCNOTTY, NULL);
                 close(fd);
          }


     TIOCNOTTY sets the process group to zero.  The next time you
     open a terminal file, that file becomes the control
     terminal.  This new association can be prevented by first
     setting the process group (see below) to some non-zero
     value.  For example,

          setpgrp(getpid());


     Process groups.

     Command processors such as csh(1csh) can arbitrate the
     terminal between different jobs by placing related jobs in a
     single process group and associating this process group with
     the terminal.  A terminals associated process group may be
     set using the TIOCSPGRP ioctl(2):

          ioctl(fildes, TIOCSPGRP, &pgrp)





Printed 10/17/86                                                2





TTY(4)                  COMMAND REFERENCE                  TTY(4)



     or examined using TIOCGPGRP rather than TIOCSPGRP, returning
     the current process group in pgrp. The new terminal driver
     aids in this arbitration by restricting access to the
     terminal by processes which are not in the current process
     group; see Job access control below.


     Modes.

     The terminal drivers have three major modes, characterized
     by the amount of processing on the input and output
     characters:

     cooked    The normal mode.  In this mode lines of input are
               collected and input editing is done.  The edited
               line is made available when it is completed by a
               newline or when an EOT (control-D, hereafter ^D)
               is entered.  A carriage return is usually made
               synonymous with newline in this mode, and replaced
               with a newline whenever it is typed.  All driver
               functions (input editing, interrupt generation,
               output processing such as delay generation and tab
               expansion, etc.) are available in this mode.

     CBREAK    This mode eliminates the character, word, and line
               editing input facilities, making the input
               character available to the user program as it is
               typed.  Flow control, literal-next and interrupt
               processing are still done in this mode.  Output
               processing is done.

     RAW       This mode eliminates all input processing and
               makes all input characters available as they are
               typed; no output processing is done either.

     The style of input processing can also be very different
     when the terminal is put in non-blocking i/o mode; see
     fcntl(2).  In this case a read(2) from the control terminal
     will never block, but rather return an error indication
     (EWOULDBLOCK) if there is no input available.

     A process may also request a SIGIO signal be sent it
     whenever input is present.  To enable this mode the FASYNC
     flag should be set using fcntl(2).


     Input editing.

     A UTek terminal ordinarily operates in full-duplex mode.
     Characters may be typed at any time, even while output is
     occurring, and are only lost when the system's character
     input buffers become completely choked, which is rare, or



Printed 10/17/86                                                3





TTY(4)                  COMMAND REFERENCE                  TTY(4)



     when the user has accumulated the maximum allowed number of
     input characters that have not yet been read by some
     program.  Currently this limit is 256 characters.  When this
     limit is reached, no more input is accepted and the terminal
     bell is rung.

     Input characters are normally accepted in either even or odd
     parity with the parity bit being stripped off before the
     character is given to the program.  By clearing either the
     EVEN or ODD bit in the flags word it is possible to have
     input characters with that parity discarded (see the
     sections Basic ioctl and Basic modes:  sgtty below.)

     In all of the line disciplines, it is possible to simulate
     terminal input using the TIOCSTI ioctl, which takes, as its
     third argument, the address of a character.  The system
     pretends that this character was typed on the argument
     terminal, which must be the control terminal except for the
     super-user (this call is not in standard version 7 UNIX).

     Input characters are normally echoed by putting them in an
     output queue as they arrive.  This may be disabled by
     clearing the ECHO bit in the flags word using the TIOCSETN
     or TIOCSETP ioctls (see the Summary below).

     In cooked mode, terminal input is processed in units of
     lines.  A program attempting to read will normally be
     suspended until an entire line has been received (but see
     the description of SIGTTIN in Job access control above and
     FIONREAD in Basic ioctl below.) No matter how many
     characters are requested in the read call, at most one line
     will be returned.  It is not, however, necessary to read a
     whole line at once; any number of characters may be
     requested in a read, even one, without losing information.

     During input, line editing is normally done, with the
     character `^H' logically erasing the last character typed
     and the character `^U' logically erasing the entire current
     input line.  These characters never erase beyond the
     beginning of the current input line or an ^D.  These
     characters may be entered literally by preceding them with
     `^V'; see below.

     The drivers normally treat either a carriage return or a
     newline character as terminating an input line, replacing
     the return with a newline and echoing a return and a line
     feed.  If the CRMOD bit is cleared in the local mode word
     then the processing for carriage return is disabled, and it
     is simply echoed as a return, and does not terminate cooked
     mode input.





Printed 10/17/86                                                4





TTY(4)                  COMMAND REFERENCE                  TTY(4)



     In both the old and the new driver there is a literal-next
     character (default ^V) which can be typed in both cooked and
     CBREAK mode preceding any character to prevent its special
     meaning.

     The new terminal driver also provides two other editing
     characters in normal mode.  The word-erase character,
     normally ^W, erases the preceding word, but not any spaces
     before it.  For the purposes of ^W, a word is defined as a
     sequence of non-blank characters, with tabs counted as
     blanks.  Finally, the reprint character, normally ^R,
     retypes the pending input beginning on a new line.

     Input echoing and redisplay

     When a kill character is typed it is echoed followed by a
     new-line.

     The new terminal driver has several modes for handling the
     echoing of terminal input, controlled by bits in a local
     mode word.

     Hardcopy terminals. When a hardcopy terminal is in use, the
     LPRTERA bit is normally set in the local mode word.
     Characters which are logically erased are then printed out
     backwards preceded by `\' and followed by `/' in this mode.

     Crt terminals. When a crt terminal is in use, the LCRTBS bit
     is normally set in the local mode word.  The terminal driver
     then echoes the proper number of erase characters when input
     is erased; in the normal case where the erase character is a
     ^H this causes the cursor of the terminal to back up to
     where it was before the logically erased character was
     typed.

     Erasing characters from a crt. When a crt terminal is in
     use, the LCRTERA bit may be set to cause input to be erased
     from the screen with a "backspace-space-backspace" sequence
     when character or word deleting sequences are used.  A
     LCRTKIL bit may be set as well, causing the input to be
     erased in this manner on line kill sequences as well.

     Echoing of control characters. If the LCTLECH bit is set in
     the local state word, then non-printing (control) characters
     are normally echoed as ^X (for some X) rather than being
     echoed unmodified; delete is echoed as ^?.

     The normal modes for using the new terminal driver on crt
     terminals are speed dependent.  At speeds less than 1200
     baud, the LCRTERA and LCRTKILL processing is painfully slow,
     so stty(1) normally just sets LCRTBS and LCTLECH; at speeds
     of 1200 baud or greater all of these bits are normally set.



Printed 10/17/86                                                5





TTY(4)                  COMMAND REFERENCE                  TTY(4)



     Stty(1) summarizes these option settings and the use of the
     new terminal driver as "newcrt."


     Output processing.

     When one or more characters are written, they are actually
     transmitted to the terminal as soon as previously-written
     characters have finished typing.  (As noted above, input
     characters are normally echoed by putting them in the output
     queue as they arrive.) When a process produces characters
     more rapidly than they can be typed, it will be suspended
     when its output queue exceeds some limit.  When the queue
     has drained down to some threshold the program is resumed.
     Even parity is normally generated on output.

     The terminal drivers provide necessary processing for cooked
     and CBREAK mode output including delay generation for
     certain special characters and parity generation.   Delays
     are available after backspaces ^H, form feeds ^L, carriage
     returns ^M, tabs ^I and newlines ^J.  The driver will also
     optionally expand tabs into spaces, where the tab stops are
     assumed to be set every eight columns.  These functions are
     controlled by bits in the tty flags word; see Summary below.

     Finally, in the new terminal driver, there is a output flush
     character, normally ^O, which sets the LFLUSHO bit in the
     local mode word, causing subsequent output to be flushed
     until it is cleared by a program or more input is typed.
     This character has effect in both cooked and CBREAK modes
     and causes pending input to be retyped if there is any
     pending input.  An ioctl to flush the characters in the
     input and output queues, TIOCFLUSH, is also available.


     Hazeltine terminals

     To deal with Hazeltine terminals, which do not understand
     that ~ has been made into an ASCII character, the LTILDE bit
     may be set in the local mode word when using the new
     terminal driver; in this case the character ~ will be
     replaced with the character ` on output.


     Flow control.

     There are two characters (the stop character, normally ^S,
     and the start character, normally ^Q) which cause output to
     be suspended and resumed respectively.  Extra stop
     characters typed when output is already stopped have no
     effect.




Printed 10/17/86                                                6





TTY(4)                  COMMAND REFERENCE                  TTY(4)



     A bit in the flags word may be set to put the terminal into
     TANDEM mode.  In this mode the system produces a stop
     character (default ^S) when the input queue is in danger of
     overflowing, and a start character (default ^Q) when the
     input has drained sufficiently.  This mode is useful when
     the terminal is actually another machine that obeys the
     conventions.


     Line control and breaks.

     There are several ioctl calls available to control the state
     of the terminal line.  The TIOCSBRK ioctl will set the break
     bit in the hardware interface causing a break condition to
     exist; this can be cleared (usually after a delay with
     sleep(3c) by TIOCCBRK.  Break conditions in the input are
     reflected as a null character in RAW mode or as the
     interrupt character in cooked or CBREAK mode.  The TIOCCDTR
     ioctl will clear the data terminal ready condition; it can
     be set again by TIOCSDTR.

     When the carrier signal from the dataset drops (usually
     because the user has hung up his terminal) a SIGHUP hangup
     signal is sent to the processes in the distinguished process
     group of the terminal; this usually causes them to terminate
     (the SIGHUP can be suppressed by setting the LNOHANG bit in
     the local state word of the driver.) Access to the terminal
     by other processes is then normally revoked, so any further
     reads will fail, and programs that read a terminal and test
     for end-of-file on their input will terminate appropriately.

     When using an ACU it is possible to ask that the phone line
     be hung up on the last close with the TIOCHPCL ioctl; this
     is normally done on the outgoing line.


     Interrupt characters.

     There are several characters that generate interrupts in
     cooked and CBREAK mode; all are sent the processes in the
     control group of the terminal, as if a TIOCGPGRP ioctl were
     done to get the process group and then a killpg(2) system
     call were done, except that these characters also flush
     pending input and output when typed at a terminal (a la
     TIOCFLUSH).  The characters shown here are the defaults; the
     field names in the structures (given below) are also shown.
     The characters may be changed, although this is not often
     done.

     ^C   tintrc (Delete) generates a SIGINT signal.  This is
          the normal way to stop a process which is no longer
          interesting, or to regain control in an interactive



Printed 10/17/86                                                7





TTY(4)                  COMMAND REFERENCE                  TTY(4)



          program.

     ^\   tquitc (FS) generates a SIGQUIT signal.  This is used
          to cause a program to terminate and produce a core
          image, if possible, in the file core in the current
          directory.

     ^Z   tsuspc (SUB) generates a SIGTSTP signal, which is used
          to suspend the current process group.

     ^Y   tdsuspc (EM) generates a SIGTSTP signal as ^Z does,
          but the signal is sent when a program attempts to read
          the ^Y, rather than when it is typed.


     Job access control.

     When using the new terminal driver, if a process which is
     not in the distinguished process group of its control
     terminal attempts to read from that terminal its process
     group is sent a SIGTTIN signal.  This signal normally causes
     the members of that process group to stop.  If, however, the
     process is ignoring SIGTTIN, has SIGTTIN blocked, is an
     orphan process, or is in the middle of process creation
     using vfork(2)), it is instead returned an end-of-file.  (An
     orphan process is a process whose parent has exited and has
     been inherited by the init(8) process.) Under older UNIX
     systems these processes would typically have had their input
     files reset to /dev/null, so this is a compatible change.

     When using the new terminal driver with the LTOSTOP bit set
     in the local modes, a process is prohibited from writing on
     its control terminal if it is not in the distinguished
     process group for that terminal.  Processes which are
     holding or ignoring SIGTTOU signals, which are orphans, or
     which are in the middle of a vfork(2) are excepted and
     allowed to produce output.


     Summary of modes.

     Unfortunately, due to the evolution of the terminal driver,
     there are 4 different structures which contain various
     portions of the driver data.  The first of these (sgttyb)
     contains that part of the information largely common between
     version 6 and version 7 UNIX systems.  The second contains
     additional control characters added in version 7.  The third
     is a word of local state peculiar to the new terminal
     driver, and the fourth is another structure of special
     characters added for the new driver.  In the future a single
     structure may be made available to programs which need to
     access all this information; most programs need not concern



Printed 10/17/86                                                8





TTY(4)                  COMMAND REFERENCE                  TTY(4)



     themselves with all this state.

     Basic modes: sgtty.

     The basic ioctls use the structure defined in <sgtty.h>:

     struct sgttyb {
          char  sgispeed;/* input speed */
          char  sgospeed;/* output speed */
          char  sgerase;/* erase character */
          char  sgkill;/* kill character */
          short sgflags;/* mode flags */
     };

     The sg_ispeed and sg_ospeed fields describe the input and
     output speeds of the device according to the following
     table.  NOTE: due to hardware limitations, sg_ispeed and
     sg_ospeed must be the same.

     Symbolic values in the table are as defined in <ttydev.h>.

     B0      0    (hang up dataphone)
     B50     1    50 baud
     B75     2    75 baud
     B110    3    110 baud
     B134    4    134.5 baud
     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   19200 baud
     EXTB    15   External B

     In the current configuration, only 110, 150, 300 and 1200
     baud are really supported on dial-up lines.  Code conversion
     and line control required for IBM 2741's (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.

     The sg_erase and sg_kill fields of the argument structure
     specify the erase and kill characters respectively.
     (Defaults are ^H and ^U.)

     The sg_flags field of the argument structure contains
     several bits that determine the system's treatment of the
     terminal:



Printed 10/17/86                                                9





TTY(4)                  COMMAND REFERENCE                  TTY(4)



     ALLDELAY 0x0000FF00 Delay algorithm selection
     BSDELAY  0x00008000 Select backspace delays (not implemented):
     BS0      0x00000000
     BS1      0x00008000
     VTDELAY  0x00004000 Select form-feed and vertical-tab delays:
     FF0      0x00000000
     FF1      0x00004000
     CRDELAY  0x00003000 Select carriage-return delays:
     CR0      0x00000000
     CR1      0x00001000
     CR2      0x00002000
     CR3      0x00003000
     TBDELAY  0x00000C00 Select tab delays:
     TAB0     0x00000000
     TAB1     0x00000400
     TAB2     0x00000800
     XTABS    0x00000C00
     NLDELAY  0x00000300 Select new-line delays:
     NL0      0x00000000
     NL1      0x00000100
     NL2      0x00000200
     NL3      0x00000300
     EVENP    0x00000080 Even parity allowed on input (most terminals)
     ODDP     0x00000040 Odd parity allowed on input
     RAW      0x00000020 Raw mode: wake up on all characters, 8-bit interface
     CRMOD    0x00000010 Map CR into LF; echo LF or CR as CR-LF
     ECHO     0x00000008 Echo (full duplex)
     LCASE    0x00000004 Map upper case to lower on input
     CBREAK   0x00000002 Return each character as soon as typed
     TANDEM   0x00000001 Automatic flow control

     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.

     Backspace delays are currently ignored but might be used for
     Terminet 300's.

     If a form-feed/vertical tab delay is specified, it lasts for
     about 2 seconds.

     Carriage-return delay type 1 lasts about 0.08 seconds and is
     suitable for the Terminet 300.  Delay type 2 lasts about
     0.16 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 9 characters at 9600 baud.

     New-line delay type 1 (about 0.12 seconds) is dependent on
     the current column and is tuned for Teletype model 37's.
     Type 2 is useful for the VT05 and is about 0.10 seconds.
     Type 3 is unimplemented and is 0.



Printed 10/17/86                                               10





TTY(4)                  COMMAND REFERENCE                  TTY(4)



     Tab delay type 1 is about 0.1 seconds and and is tuned to
     the Teletype model 37.  Type 2 is not implemented.  Type 3,
     called XTABS, is not a delay at all but causes tabs to be
     replaced by the appropriate number of spaces on output.

     Input characters with the wrong parity, as determined by
     bits 200 and 100, are ignored in cooked and CBREAK mode.

     RAW disables all processing save output flushing with
     LFLUSHO; full 8 bits of input are given as soon as it is
     available; all 8 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.

     CRMOD causes input carriage returns to be turned into new-
     lines; input of either CR or LF causes LF-CR both to be
     echoed (for terminals with a new-line function).

     CBREAK is a sort of half-cooked (rare?) 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 \ or EOT are disabled.

     TANDEM mode causes the system to produce a stop character
     (default is ^S) whenever the input queue is in danger of
     overflowing, and a start character (default is ^Q) when the
     input queue has drained sufficiently.  It is useful for flow
     control when the `terminal' is really another computer which
     understands the conventions.

     DODTR and DOCTS provide a hardware flow control mechanism.
     DODTR works much like TANDEM in that when the buffer
     approaches being full, the DTR line is deasserted; when the
     buffer is emptied DTR is reasserted.  DOCTS causes the USART
     to transmit or not depending on the state of the CTS pin.

     Basic ioctls

     In addition to the TIOCSETD and TIOCGETD disciplines
     discussed in Line disciplines above, a large number of other
     ioctl(2) calls apply to terminals, and have the general
     form:

     #include <sgtty.h>

     ioctl(fildes, code, arg)
     struct sgttyb *arg;

     The applicable codes are:




Printed 10/17/86                                               11





TTY(4)                  COMMAND REFERENCE                  TTY(4)



     TIOCEXCL       Set "exclusive-use" mode:  no further opens
                    are permitted until the file has been closed.

     TIOCGETP       Fetch the basic parameters associated with
                    the terminal, and store in the pointed-to
                    sgttyb structure.

     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.

     TIOCNXCL       Turn off "exclusive-use" mode.

     TIOCSETP       Set the parameters according to the pointed-
                    to sgttyb structure.  The interface delays
                    until output is quiescent, then throws away
                    any unread characters, before changing the
                    modes.

     TIOCSETN       Set the parameters like TIOCSETP but do not
                    delay or flush input.  Input is not
                    preserved, however, when changing to or from
                    RAW.

     TIOCSTART      Simulates the use of <CTRL-Q>.

     TIOCSTOP       Simulates the use of <CTRL-S>.

     TIOCNOTTY      Breaks the association between a process and
                    its control terminal.

     The remaining calls are not available in vanilla version 7
     UNIX.  In cases where arguments are required, they are
     described; arg should otherwise be given as 0.

     TIOCSTI        the argument is the address of a character
                    which the system pretends was typed on the
                    terminal.

     TIOCSBRK       the break bit is set in the terminal.

     TIOCCBRK       the break bit is cleared.

     TIOCSDTR       data terminal ready is set.

     TIOCCDTR       data terminal ready is cleared.

     TIOCGPGRP      arg is the address of a word into which is
                    placed the process group number of the
                    control terminal.




Printed 10/17/86                                               12





TTY(4)                  COMMAND REFERENCE                  TTY(4)



     TIOCSPGRP      arg is a word (typically a process id) which
                    becomes the process group for the control
                    terminal.

     FIONREAD       returns in the long integer whose address is
                    arg the number of immediately readable
                    characters from the argument unit.  This
                    works for files, pipes, terminals, and
                    sockets.

     The following call uses a different structure than do the
     previous calls:

     #include <sys/file.h>
     ioctl(filedes, code, arg)
     int *arg;

     TIOCFLUSH
          Flush all characters waiting in input and/or output
          queues, based on whether FREAD (input), FWRITE (output)
          or both have been set in the word pointed to by arg.
          If that word is 0, both input and output queues will be
          flushed.  This last feature is provided for
          compatibility with 4.1c BSD.

     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
     <sys/ioctl.h>, which is automatically included in <sgtty.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) */
     };


     The default values for these characters are ^?, ^\, ^Q, ^S,
     ^D, and -1.  A character value of -1 eliminates the effect
     of that character.  The t_brkc character, by default -1,
     acts like a new-line in that it terminates a `line,' is
     echoed, and is passed to the program.  The `stop' and
     `start' 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:




Printed 10/17/86                                               13





TTY(4)                  COMMAND REFERENCE                  TTY(4)



     TIOCGETC    Get the special characters and put them in the
                 specified structure.

     TIOCSETC    Set the special characters to those given in the
                 structure.

     Local mode

     The third structure associated with each terminal is a local
     mode word; except for the LNOHANG bit, this word is
     interpreted only when the new driver is in use.  The bits of
     the local mode word are:

     LCRTBS   0x0001  Backspace on erase rather than echoing erase
     LPRTERA  0x0002  Printing terminal erase mode
     LCRTERA  0x0004  Erase character echoes as BS-space-BS
     LTILDE   0x0008  Convert ~ to ` on output (Hazeltine terminals)
     LMDMBUF  0x0010  Stop/start output when carrier drops
     LLITOUT  0x0020  Suppress output translations
     LTOSTOP  0x0040  Send SIGTTOU for background output
     LFLUSHO  0x0080  Output is being flushed
     LNOHANG  0x0100  Don't send hangup when carrier drops
     LDODTR   0x0200  Automatic flow control using DTR
     LCRTKIL  0x0400  BS-space-BS erase entire line on line kill
     LDOCTS   0x0800  Transmission conditional on CTS
     LCTLECH  0x1000  Echo input control chars as ^X, delete as ^?
     LPENDIN  0x2000  Retype pending input at next read or input
     LDECCTQ  0x4000  Only ^Q restarts output after ^S, like DEC
     LNOFLSH  0x8000  Don't flush output on interrupt/suspend

     The applicable ioctl functions are:

     TIOCLBIS       arg is the address of a mask which is the
                    bits to be set in the local mode word.

     TIOCLBIC       arg is the address of a mask of bits to be
                    cleared in the local mode word.

     TIOCLSET       arg is the address of a mask to be placed in
                    the local mode word.

     TIOCLGET       arg is the address of a word into which the
                    current mask is placed.

     Local special chars

     The final structure associated with each terminal is the
     ltchars structure, defined in <sys/ttychars.h>, which
     defines interrupt characters for the new terminal driver.
     Its structure is:

     struct ltchars {



Printed 10/17/86                                               14





TTY(4)                  COMMAND REFERENCE                  TTY(4)



             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 default values for these characters are ^Z, ^Y, ^R, ^O,
     ^W, and ^V.  A value of -1 disables the character.

     The applicable ioctl functions are:

     TIOCSLTC    args is the address of a ltchars structure which
                 defines the new local special characters.

     TIOCGLTC    args is the address of a ltchars structure into
                 which is placed the current set of local special
                 characters.

FILES
     /dev/tty

     /dev/tty*

     /dev/console

CAVEATS
     Half-duplex terminals are not supported.

SEE ALSO
     csh(1csh), stty(1), ioctl(2), sigvec(2), getty(8), init(8).






















Printed 10/17/86                                               15





































































%%index%%
na:72,102;
sy:174,184;
de:358,2225;2727,2461;5332,2489;7965,2772;10881,2807;13832,2454;16430,2722;19296,2790;22230,2904;25278,2135;27557,2688;30389,2078;32611,2499;35254,2240;37638,875;
fi:38513,132;
ca:38645,97;
se:38742,189;
%%index%%000000000260

Typewritten Software • bear@typewritten.org • Edmonds, WA 98026