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man:tcsendbreak

TERMIOS(3) Linux Programmer's Manual TERMIOS(3)

NAME

     termios,  tcgetattr,  tcsetattr, tcsendbreak, tcdrain, tcflush, tcflow,
     cfmakeraw, cfgetospeed, cfgetispeed, cfsetispeed,  cfsetospeed,  cfset-
     speed - get and set terminal attributes, line control, get and set baud
     rate

SYNOPSIS

     #include <termios.h>
     #include <unistd.h>
     int tcgetattr(int fd, struct termios *termios_p);
     int tcsetattr(int fd, int optional_actions,
                   const struct termios *termios_p);
     int tcsendbreak(int fd, int duration);
     int tcdrain(int fd);
     int tcflush(int fd, int queue_selector);
     int tcflow(int fd, int action);
     void cfmakeraw(struct termios *termios_p);
     speed_t cfgetispeed(const struct termios *termios_p);
     speed_t cfgetospeed(const struct termios *termios_p);
     int cfsetispeed(struct termios *termios_p, speed_t speed);
     int cfsetospeed(struct termios *termios_p, speed_t speed);
     int cfsetspeed(struct termios *termios_p, speed_t speed);
 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
     cfsetspeed(), cfmakeraw():
         Since glibc 2.19:
             _DEFAULT_SOURCE
         Glibc 2.19 and earlier:
             _BSD_SOURCE

DESCRIPTION

     The termios functions describe a general  terminal  interface  that  is
     provided to control asynchronous communications ports.
 The termios structure
     Many  of the functions described here have a termios_p argument that is
     a pointer to a termios structure.  This structure contains at least the
     following members:
         tcflag_t  c_iflag;      /* input modes */ tcflag_t c_oflag;      /*
         output modes */ tcflag_t c_cflag;      /* control modes */ tcflag_t
         c_lflag;       /*  local modes */ cc_t     c_cc[NCCS];   /* special
         characters */
     The values that may be assigned to these fields  are  described  below.
     In  the case of the first four bit-mask fields, the definitions of some
     of the associated flags that may be set are exposed only if a  specific
     feature test macro (see feature_test_macros(7)) is defined, as noted in
     brackets ("[]").
     In the descriptions below, "not in POSIX" means that the value  is  not
     specified  in POSIX.1-2001, and "XSI" means that the value is specified
     in POSIX.1-2001 as part of the XSI extension.
     c_iflag flag constants:
     IGNBRK Ignore BREAK condition on input.
     BRKINT If IGNBRK is set, a BREAK is ignored.  If  it  is  not  set  but
            BRKINT  is  set, then a BREAK causes the input and output queues
            to be flushed, and if the terminal is the  controlling  terminal
            of a foreground process group, it will cause a SIGINT to be sent
            to this foreground  process  group.   When  neither  IGNBRK  nor
            BRKINT are set, a BREAK reads as a null byte ('\0'), except when
            PARMRK is set, in which case it reads as the  sequence  \377  \0
            \0.
     IGNPAR Ignore framing errors and parity errors.
     PARMRK If  this  bit  is set, input bytes with parity or framing errors
            are marked when passed to the program.  This bit  is  meaningful
            only when INPCK is set and IGNPAR is not set.  The way erroneous
            bytes are marked is with  two  preceding  bytes,  \377  and  \0.
            Thus,  the  program actually reads three bytes for one erroneous
            byte received from the terminal.  If a valid byte has the  value
            \377,  and ISTRIP (see below) is not set, the program might con-
            fuse it with the prefix that marks a parity error.  Therefore, a
            valid  byte  \377  is  passed  to the program as two bytes, \377
            \377, in this case.
            If neither IGNPAR nor PARMRK is set, read  a  character  with  a
            parity error or framing error as \0.
     INPCK  Enable input parity checking.
     ISTRIP Strip off eighth bit.
     INLCR  Translate NL to CR on input.
     IGNCR  Ignore carriage return on input.
     ICRNL  Translate  carriage  return to newline on input (unless IGNCR is
            set).
     IUCLC  (not in POSIX) Map uppercase characters to lowercase on input.
     IXON   Enable XON/XOFF flow control on output.
     IXANY  (XSI) Typing any character will restart  stopped  output.   (The
            default is to allow just the START character to restart output.)
     IXOFF  Enable XON/XOFF flow control on input.
     IMAXBEL
            (not in POSIX) Ring bell when input queue is full.   Linux  does
            not implement this bit, and acts as if it is always set.
     IUTF8 (since Linux 2.6.4)
            (not  in POSIX) Input is UTF8; this allows character-erase to be
            correctly performed in cooked mode.
     c_oflag flag constants:
     OPOST  Enable implementation-defined output processing.
     OLCUC  (not in POSIX) Map lowercase characters to uppercase on  output.
     ONLCR  (XSI) Map NL to CR-NL on output.
     OCRNL  Map CR to NL on output.
     ONOCR  Don't output CR at column 0.
     ONLRET Don't output CR.
     OFILL  Send  fill  characters  for  a  delay, rather than using a timed
            delay.
     OFDEL  Fill character is ASCII DEL (0177).  If unset, fill character is
            ASCII NUL ('\0').  (Not implemented on Linux.)
     NLDLY  Newline   delay  mask.   Values  are  NL0  and  NL1.   [requires
            _BSD_SOURCE or _SVID_SOURCE or _XOPEN_SOURCE]
     CRDLY  Carriage return delay mask.  Values are CR0, CR1, CR2,  or  CR3.
            [requires _BSD_SOURCE or _SVID_SOURCE or _XOPEN_SOURCE]
     TABDLY Horizontal  tab  delay  mask.  Values are TAB0, TAB1, TAB2, TAB3
            (or XTABS).  A value of TAB3, that is, XTABS,  expands  tabs  to
            spaces   (with   tab  stops  every  eight  columns).   [requires
            _BSD_SOURCE or _SVID_SOURCE or _XOPEN_SOURCE]
     BSDLY  Backspace delay mask.  Values are BS0 or BS1.  (Has  never  been
            implemented.)    [requires   _BSD_SOURCE   or   _SVID_SOURCE  or
            _XOPEN_SOURCE]
     VTDLY  Vertical tab delay mask.  Values are VT0 or VT1.
     FFDLY  Form feed  delay  mask.   Values  are  FF0  or  FF1.   [requires
            _BSD_SOURCE or _SVID_SOURCE or _XOPEN_SOURCE]
     c_cflag flag constants:
     CBAUD  (not   in   POSIX)   Baud  speed  mask  (4+1  bits).   [requires
            _BSD_SOURCE or _SVID_SOURCE]
     CBAUDEX
            (not in POSIX) Extra baud speed mask (1 bit), included in CBAUD.
            [requires _BSD_SOURCE or _SVID_SOURCE]
            (POSIX  says that the baud speed is stored in the termios struc-
            ture  without   specifying   where   precisely,   and   provides
            cfgetispeed() and cfsetispeed() for getting at it.  Some systems
            use bits selected by CBAUD in c_cflag, other systems  use  sepa-
            rate fields, for example, sg_ispeed and sg_ospeed.)
     CSIZE  Character size mask.  Values are CS5, CS6, CS7, or CS8.
     CSTOPB Set two stop bits, rather than one.
     CREAD  Enable receiver.
     PARENB Enable  parity  generation  on  output  and  parity checking for
            input.
     PARODD If set, then parity for input and output is odd; otherwise  even
            parity is used.
     HUPCL  Lower  modem  control lines after last process closes the device
            (hang up).
     CLOCAL Ignore modem control lines.
     LOBLK  (not in POSIX) Block output from a noncurrent shell layer.   For
            use by shl (shell layers).  (Not implemented on Linux.)
     CIBAUD (not in POSIX) Mask for input speeds.  The values for the CIBAUD
            bits are the same as the values for the CBAUD bits, shifted left
            IBSHIFT  bits.   [requires  _BSD_SOURCE  or  _SVID_SOURCE]  (Not
            implemented on Linux.)
     CMSPAR (not in POSIX) Use "stick"  (mark/space)  parity  (supported  on
            certain  serial  devices):  if  PARODD is set, the parity bit is
            always 1; if PARODD is not set, then the parity bit is always 0.
            [requires _BSD_SOURCE or _SVID_SOURCE]
     CRTSCTS
            (not   in   POSIX)   Enable  RTS/CTS  (hardware)  flow  control.
            [requires _BSD_SOURCE or _SVID_SOURCE]
     c_lflag flag constants:
     ISIG   When any of the  characters  INTR,  QUIT,  SUSP,  or  DSUSP  are
            received, generate the corresponding signal.
     ICANON Enable canonical mode (described below).
     XCASE  (not in POSIX; not supported under Linux) If ICANON is also set,
            terminal is uppercase only.  Input is  converted  to  lowercase,
            except for characters preceded by \.  On output, uppercase char-
            acters are preceded by \ and lowercase characters are  converted
            to   uppercase.    [requires   _BSD_SOURCE  or  _SVID_SOURCE  or
            _XOPEN_SOURCE]
     ECHO   Echo input characters.
     ECHOE  If ICANON is also set, the ERASE character erases the  preceding
            input character, and WERASE erases the preceding word.
     ECHOK  If  ICANON  is  also  set, the KILL character erases the current
            line.
     ECHONL If ICANON is also set, echo the NL character even if ECHO is not
            set.
     ECHOCTL
            (not  in POSIX) If ECHO is also set, terminal special characters
            other than TAB, NL, START, and STOP are echoed as ^X, where X is
            the  character  with  ASCII  code  0x40 greater than the special
            character.  For example, character 0x08 (BS) is  echoed  as  ^H.
            [requires _BSD_SOURCE or _SVID_SOURCE]
     ECHOPRT
            (not  in  POSIX) If ICANON and ECHO are also set, characters are
            printed as they are  being  erased.   [requires  _BSD_SOURCE  or
            _SVID_SOURCE]
     ECHOKE (not  in POSIX) If ICANON is also set, KILL is echoed by erasing
            each character on the line, as specified by ECHOE  and  ECHOPRT.
            [requires _BSD_SOURCE or _SVID_SOURCE]
     DEFECHO
            (not in POSIX) Echo only when a process is reading.  (Not imple-
            mented on Linux.)
     FLUSHO (not in POSIX;  not  supported  under  Linux)  Output  is  being
            flushed.   This flag is toggled by typing the DISCARD character.
            [requires _BSD_SOURCE or _SVID_SOURCE]
     NOFLSH Disable flushing the input and  output  queues  when  generating
            signals for the INT, QUIT, and SUSP characters.
     TOSTOP Send  the  SIGTTOU  signal  to the process group of a background
            process which tries to write to its controlling terminal.
     PENDIN (not in POSIX; not supported under Linux) All characters in  the
            input  queue  are  reprinted  when  the  next character is read.
            (bash(1) handles typeahead this way.)  [requires _BSD_SOURCE  or
            _SVID_SOURCE]
     IEXTEN Enable  implementation-defined  input processing.  This flag, as
            well as ICANON must be enabled for the special characters  EOL2,
            LNEXT, REPRINT, WERASE to be interpreted, and for the IUCLC flag
            to be effective.
     The c_cc array defines the terminal special characters.   The  symbolic
     indices (initial values) and meaning are:
     VDISCARD
            (not  in POSIX; not supported under Linux; 017, SI, Ctrl-O) Tog-
            gle: start/stop discarding pending output.  Recognized when IEX-
            TEN is set, and then not passed as input.
     VDSUSP (not  in  POSIX;  not  supported  under  Linux; 031, EM, Ctrl-Y)
            Delayed suspend character (DSUSP): send SIGTSTP signal when  the
            character  is  read by the user program.  Recognized when IEXTEN
            and ISIG are set, and the system supports job control, and  then
            not passed as input.
     VEOF   (004, EOT, Ctrl-D) End-of-file character (EOF).  More precisely:
            this character causes the pending tty buffer to be sent  to  the
            waiting  user program without waiting for end-of-line.  If it is
            the first character of the line, the read(2) in the user program
            returns  0, which signifies end-of-file.  Recognized when ICANON
            is set, and then not passed as input.
     VEOL   (0, NUL) Additional  end-of-line  character  (EOL).   Recognized
            when ICANON is set.
     VEOL2  (not in POSIX; 0, NUL) Yet another end-of-line character (EOL2).
            Recognized when ICANON is set.
     VERASE (0177, DEL, rubout, or 010, BS, Ctrl-H, or also #) Erase charac-
            ter (ERASE).  This erases the previous not-yet-erased character,
            but does not erase past EOF  or  beginning-of-line.   Recognized
            when ICANON is set, and then not passed as input.
     VINTR  (003,  ETX, Ctrl-C, or also 0177, DEL, rubout) Interrupt charac-
            ter (INTR).  Send a SIGINT signal.  Recognized when ISIG is set,
            and then not passed as input.
     VKILL  (025,  NAK, Ctrl-U, or Ctrl-X, or also @) Kill character (KILL).
            This erases the input since the last EOF  or  beginning-of-line.
            Recognized when ICANON is set, and then not passed as input.
     VLNEXT (not  in  POSIX; 026, SYN, Ctrl-V) Literal next (LNEXT).  Quotes
            the next input character, depriving it  of  a  possible  special
            meaning.   Recognized when IEXTEN is set, and then not passed as
            input.
     VMIN   Minimum number of characters for noncanonical read (MIN).
     VQUIT  (034, FS, Ctrl-\) Quit character (QUIT).  Send  SIGQUIT  signal.
            Recognized when ISIG is set, and then not passed as input.
     VREPRINT
            (not  in POSIX; 022, DC2, Ctrl-R) Reprint unread characters (RE-
            PRINT).  Recognized when ICANON and IEXTEN are set, and then not
            passed as input.
     VSTART (021,  DC1,  Ctrl-Q)  Start  character (START).  Restarts output
            stopped by the Stop character.  Recognized when IXON is set, and
            then not passed as input.
     VSTATUS
            (not  in  POSIX; not supported under Linux; status request: 024,
            DC4, Ctrl-T).  Status character (STATUS).  Display status infor-
            mation  at  terminal,  including state of foreground process and
            amount of CPU time it has consumed.  Also sends a SIGINFO signal
            (not supported on Linux) to the foreground process group.
     VSTOP  (023,  DC3,  Ctrl-S)  Stop  character (STOP).  Stop output until
            Start character typed.  Recognized when IXON is  set,  and  then
            not passed as input.
     VSUSP  (032,  SUB, Ctrl-Z) Suspend character (SUSP).  Send SIGTSTP sig-
            nal.  Recognized when ISIG is set, and then not passed as input.
     VSWTCH (not in POSIX; not supported under Linux; 0, NUL) Switch charac-
            ter (SWTCH).  Used in System V to switch shells in shell layers,
            a predecessor to shell job control.
     VTIME  Timeout in deciseconds for noncanonical read (TIME).
     VWERASE
            (not  in  POSIX;  027, ETB, Ctrl-W) Word erase (WERASE).  Recog-
            nized when ICANON and IEXTEN are set, and  then  not  passed  as
            input.
     An individual terminal special character can be disabled by setting the
     value of the corresponding c_cc element to _POSIX_VDISABLE.
     The above symbolic subscript values  are  all  different,  except  that
     VTIME,  VMIN  may  have the same value as VEOL, VEOF, respectively.  In
     noncanonical mode the special character  meaning  is  replaced  by  the
     timeout  meaning.   For  an  explanation  of  VMIN  and  VTIME, see the
     description of noncanonical mode below.
 Retrieving and changing terminal settings
     tcgetattr() gets the parameters associated with the object referred  by
     fd  and  stores  them in the termios structure referenced by termios_p.
     This function may be invoked from a background  process;  however,  the
     terminal  attributes  may  be  subsequently  changed  by  a  foreground
     process.
     tcsetattr() sets the parameters associated with  the  terminal  (unless
     support is required from the underlying hardware that is not available)
     from the termios structure referred to by termios_p.   optional_actions
     specifies when the changes take effect:
     TCSANOW
            the change occurs immediately.
     TCSADRAIN
            the change occurs after all output written to fd has been trans-
            mitted.  This option should be  used  when  changing  parameters
            that affect output.
     TCSAFLUSH
            the  change  occurs  after  all  output  written  to  the object
            referred by fd has been transmitted, and all input that has been
            received  but  not  read  will be discarded before the change is
            made.
 Canonical and noncanonical mode
     The setting of the ICANON canon flag in c_lflag determines whether  the
     terminal  is  operating  in canonical mode (ICANON set) or noncanonical
     mode (ICANON unset).  By default, ICANON is set.
     In canonical mode:
  • Input is made available line by line. An input line is available

when one of the line delimiters is typed (NL, EOL, EOL2; or EOF at

       the start of line).  Except in the case of EOF, the line delimiter is
       included in the buffer returned by read(2).
  • Line editing is enabled (ERASE, KILL; and if the IEXTEN flag is set:

WERASE, REPRINT, LNEXT). A read(2) returns at most one line of

       input; if the read(2) requested fewer bytes than are available in the
       current line of input, then only as many bytes as requested are read,
       and  the remaining characters will be available for a future read(2).
  • The maximum line length is 4096 chars (including the terminating new-

line character); lines longer than 4096 chars are truncated. After

       4095 characters, input processing (e.g., ISIG and  ECHO*  processing)
       continues,  but  any  input data after 4095 characters up to (but not
       including) any terminating newline is discarded.  This  ensures  that
       the  terminal  can  always receive more input until at least one line
       can be read.
     In noncanonical mode input is available immediately (without  the  user
     having to type a line-delimiter character), no input processing is per-
     formed, and line editing is disabled.  The read buffer will only accept
     4095 chars; this provides the necessary space for a newline char if the
     input mode is switched to canonical.  The settings of MIN  (c_cc[VMIN])
     and  TIME  (c_cc[VTIME]) determine the circumstances in which a read(2)
     completes; there are four distinct cases:
     MIN == 0, TIME == 0 (polling read)
            If data is available,  read(2)  returns  immediately,  with  the
            lesser  of the number of bytes available, or the number of bytes
            requested.  If no data is available, read(2) returns 0.
     MIN > 0, TIME == 0 (blocking read)
            read(2) blocks until MIN bytes are available, and returns up  to
            the number of bytes requested.
     MIN == 0, TIME > 0 (read with timeout)
            TIME specifies the limit for a timer in tenths of a second.  The
            timer is started when read(2) is called.  read(2) returns either
            when  at  least one byte of data is available, or when the timer
            expires.  If the timer expires without any input becoming avail-
            able,  read(2)  returns  0.  If data is already available at the
            time of the call to read(2), the call behaves as though the data
            was received immediately after the call.
     MIN > 0, TIME > 0 (read with interbyte timeout)
            TIME  specifies  the  limit  for  a timer in tenths of a second.
            Once an initial byte of input becomes available,  the  timer  is
            restarted  after each further byte is received.  read(2) returns
            when any of the following conditions is met:
  • MIN bytes have been received.
  • The interbyte timer expires.
  • The number of bytes requested by read(2) has been received.

(POSIX does not specify this termination condition, and on

               some other implementations read(2) does not  return  in  this
               case.)
            Because the timer is started only after the initial byte becomes
            available, at least one byte will be read.  If data  is  already
            available  at  the time of the call to read(2), the call behaves
            as though the data was received immediately after the call.
     POSIX does not specify whether the setting of the O_NONBLOCK file  sta-
     tus  flag  takes  precedence over the MIN and TIME settings.  If O_NON-
     BLOCK is set, a read(2) in noncanonical mode  may  return  immediately,
     regardless  of  the setting of MIN or TIME.  Furthermore, if no data is
     available, POSIX permits a  read(2)  in  noncanonical  mode  to  return
     either 0, or -1 with errno set to EAGAIN.
 Raw mode
     cfmakeraw()  sets  the terminal to something like the "raw" mode of the
     old Version 7 terminal driver: input is available character by  charac-
     ter,  echoing is disabled, and all special processing of terminal input
     and output characters is disabled.  The terminal attributes are set  as
     follows:
         termios_p->c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP
                         | INLCR | IGNCR | ICRNL | IXON); termios_p->c_oflag
         &= ~OPOST; termios_p->c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG  |
         IEXTEN);     termios_p->c_cflag     &=     ~(CSIZE    |    PARENB);
         termios_p->c_cflag |= CS8;
 Line control
     tcsendbreak() transmits a continuous stream of zero-valued bits  for  a
     specific  duration,  if  the terminal is using asynchronous serial data
     transmission.  If duration is zero, it transmits zero-valued  bits  for
     at  least  0.25 seconds, and not more that 0.5 seconds.  If duration is
     not zero, it sends zero-valued  bits  for  some  implementation-defined
     length of time.
     If  the  terminal  is  not using asynchronous serial data transmission,
     tcsendbreak() returns without taking any action.
     tcdrain() waits until all output written to the object referred  to  by
     fd has been transmitted.
     tcflush() discards data written to the object referred to by fd but not
     transmitted, or data received but not read, depending on the  value  of
     queue_selector:
     TCIFLUSH
            flushes data received but not read.
     TCOFLUSH
            flushes data written but not transmitted.
     TCIOFLUSH
            flushes  both  data  received but not read, and data written but
            not transmitted.
     tcflow() suspends transmission or  reception  of  data  on  the  object
     referred to by fd, depending on the value of action:
     TCOOFF suspends output.
     TCOON  restarts suspended output.
     TCIOFF transmits a STOP character, which stops the terminal device from
            transmitting data to the system.
     TCION  transmits a START character, which starts  the  terminal  device
            transmitting data to the system.
     The  default  on  open of a terminal file is that neither its input nor
     its output is suspended.
 Line speed
     The baud rate functions are provided for getting and setting the values
     of  the  input and output baud rates in the termios structure.  The new
     values do not take effect until tcsetattr() is successfully called.
     Setting the speed to B0 instructs the modem to "hang up".   The  actual
     bit rate corresponding to B38400 may be altered with setserial(8).
     The input and output baud rates are stored in the termios structure.
     cfgetospeed() returns the output baud rate stored in the termios struc-
     ture pointed to by termios_p.
     cfsetospeed() sets the output baud rate stored in the termios structure
     pointed to by termios_p to speed, which must be one of these constants:
          B0
          B50
          B75
          B110
          B134
          B150
          B200
          B300
          B600
          B1200
          B1800
          B2400
          B4800
          B9600
          B19200
          B38400
          B57600
          B115200
          B230400
     The zero baud rate, B0, is used to terminate the connection.  If B0  is
     specified,  the  modem control lines shall no longer be asserted.  Nor-
     mally, this will disconnect the line.  CBAUDEX is a mask for the speeds
     beyond  those  defined  in  POSIX.1  (57600 and above).  Thus, B57600 &
     CBAUDEX is nonzero.
     cfgetispeed() returns the input baud rate stored in the termios  struc-
     ture.
     cfsetispeed()  sets the input baud rate stored in the termios structure
     to speed, which must be specified as one of the Bnnn  constants  listed
     above  for  cfsetospeed().   If the input baud rate is set to zero, the
     input baud rate will be equal to the output baud rate.
     cfsetspeed() is a 4.4BSD extension.  It takes  the  same  arguments  as
     cfsetispeed(), and sets both input and output speed.

RETURN VALUE

     cfgetispeed()  returns the input baud rate stored in the termios struc-
     ture.
     cfgetospeed() returns the output baud rate stored in the termios struc-
     ture.
     All other functions return:
     0      on success.
  1. 1 on failure and set errno to indicate the error.
     Note  that  tcsetattr() returns success if any of the requested changes
     could be successfully carried out.   Therefore,  when  making  multiple
     changes  it may be necessary to follow this call with a further call to
     tcgetattr() to check that all changes have been performed successfully.

ATTRIBUTES

     For   an   explanation   of   the  terms  used  in  this  section,  see
     attributes(7).
     allbox; lbw36 lb lb l l l.  Interface Attribute Value T{ tcgetattr(),
     tcsetattr(), tcdrain(), tcflush(), tcflow(), tcsendbreak(),
     cfmakeraw(), cfgetispeed(), cfgetospeed(), cfsetispeed(),
     cfsetospeed(), cfsetspeed() T}   Thread safety  MT-Safe

CONFORMING TO

     tcgetattr(),    tcsetattr(),   tcsendbreak(),   tcdrain(),   tcflush(),
     tcflow(),  cfgetispeed(),  cfgetospeed(),  cfsetispeed(),   and   cfse-
     tospeed() are specified in POSIX.1-2001.
     cfmakeraw()  and cfsetspeed() are nonstandard, but available on the BS-
     Ds.

NOTES

     UNIX V7 and several later systems have a list of baud rates where after
     the  fourteen  values  B0, ..., B9600 one finds the two constants EXTA,
     EXTB ("External A" and "External B").  Many  systems  extend  the  list
     with much higher baud rates.
     The  effect  of  a  nonzero  duration with tcsendbreak() varies.  SunOS
     specifies a break of duration * N seconds, where N is  at  least  0.25,
     and  not more than 0.5.  Linux, AIX, DU, Tru64 send a break of duration
     milliseconds.  FreeBSD and NetBSD and HP-UX and MacOS ignore the  value
     of  duration.   Under  Solaris and UnixWare, tcsendbreak() with nonzero
     duration behaves like tcdrain().

SEE ALSO

     reset(1), setterm(1), stty(1),  tput(1),  tset(1),  tty(1),  ioctl_con-
     sole(2), ioctl_tty(2), setserial(8)

COLOPHON

     This  page  is  part of release 4.16 of the Linux man-pages project.  A
     description of the project, information about reporting bugs,  and  the
     latest     version     of     this    page,    can    be    found    at
     https://www.kernel.org/doc/man-pages/.

Linux 2017-09-15 TERMIOS(3)

/data/webs/external/dokuwiki/data/pages/man/tcsendbreak.txt · Last modified: 2019/05/17 09:47 by 127.0.0.1

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