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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(): _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 IGNPAR	is not set, prefix a character with a parity error  or
	      framing  error  with  \377  \0.  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 de-
	      lay.

       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 in-
	      put.

       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 im-
	      plemented	on Linux.)

       CMSPAR (not in POSIX) Use "stick"  (mark/space)	parity	(supported  on
	      certain serial devices): if PARODD is set, the parity bit	is al-
	      ways 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.  [re-
	      quires _BSD_SOURCE or _SVID_SOURCE]

       c_lflag flag constants:

       ISIG   When any of the characters INTR, QUIT, SUSP, or  DSUSP  are  re-
	      ceived, 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) De-
	      layed 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 in-
	      put.

       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  de-
       scription 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  re-
	      ferred  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	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 in-
	 put; 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).

       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 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  ei-
       ther 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, tc-
       sendbreak() 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 re-
       ferred 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 cf-
       setispeed(), 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     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
   Multithreading (see pthreads(7))
       The  tcgetattr(),  tcsetattr(),	tcsendbreak(),	tcdrain(),  tcflush(),
       tcflow(), cfmakeraw(), cfgetispeed(), cfgetospeed(), cfsetispeed(), cf-
       setospeed(), and	cfsetspeed() functions are thread-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
       BSDs.

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
       stty(1),	console_ioctl(4), tty_ioctl(4),	setserial(8)

COLOPHON
       This  page  is  part of release 3.74 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
       http://www.kernel.org/doc/man-pages/.

Linux				  2014-05-08			    TERMIOS(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ATTRIBUTES | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

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