1TCSENDBREAK(3P)            POSIX Programmer's Manual           TCSENDBREAK(3P)
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PROLOG

6       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
7       implementation of this interface may differ (consult the  corresponding
8       Linux  manual page for details of Linux behavior), or the interface may
9       not be implemented on Linux.
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NAME

12       tcsendbreak — send a break for a specific duration
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SYNOPSIS

15       #include <termios.h>
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17       int tcsendbreak(int fildes, int duration);
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DESCRIPTION

20       If the terminal is using asynchronous serial data transmission, tcsend‐
21       break()  shall cause transmission of a continuous stream of zero-valued
22       bits for a specific duration. If duration is 0, it shall  cause  trans‐
23       mission  of  zero-valued  bits  for at least 0.25 seconds, and not more
24       than 0.5 seconds. If duration is not 0, it shall send zero-valued  bits
25       for an implementation-defined period of time.
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27       The fildes argument is an open file descriptor associated with a termi‐
28       nal.
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30       If the terminal is not using asynchronous serial data transmission,  it
31       is  implementation-defined whether tcsendbreak() sends data to generate
32       a break condition or returns without taking any action.
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34       Attempts to use tcsendbreak() from a process which is  a  member  of  a
35       background  process  group  on a fildes associated with its controlling
36       terminal shall cause the process group to be sent a SIGTTOU signal.  If
37       the calling thread is blocking SIGTTOU signals or the process is ignor‐
38       ing SIGTTOU signals, the process shall be allowed to perform the opera‐
39       tion, and no signal is sent.
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RETURN VALUE

42       Upon successful completion, 0 shall be returned. Otherwise, -1 shall be
43       returned and errno set to indicate the error.
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ERRORS

46       The tcsendbreak() function shall fail if:
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48       EBADF  The fildes argument is not a valid file descriptor.
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50       EIO    The process group of the writing process is orphaned, the  call‐
51              ing  thread  is  not  blocking  SIGTTOU,  and the process is not
52              ignoring SIGTTOU.
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54       ENOTTY The file associated with fildes is not a terminal.
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56       The following sections are informative.
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EXAMPLES

59       None.
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APPLICATION USAGE

62       None.
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RATIONALE

65       None.
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FUTURE DIRECTIONS

68       None.
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SEE ALSO

71       The Base Definitions volume of POSIX.1‐2017, Chapter 11, General Termi‐
72       nal Interface, <termios.h>
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75       Portions  of  this text are reprinted and reproduced in electronic form
76       from IEEE Std 1003.1-2017, Standard for Information Technology --  Por‐
77       table  Operating System Interface (POSIX), The Open Group Base Specifi‐
78       cations Issue 7, 2018 Edition, Copyright (C) 2018 by the  Institute  of
79       Electrical  and  Electronics Engineers, Inc and The Open Group.  In the
80       event of any discrepancy between this version and the original IEEE and
81       The  Open Group Standard, the original IEEE and The Open Group Standard
82       is the referee document. The original Standard can be  obtained  online
83       at http://www.opengroup.org/unix/online.html .
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85       Any  typographical  or  formatting  errors that appear in this page are
86       most likely to have been introduced during the conversion of the source
87       files  to  man page format. To report such errors, see https://www.ker‐
88       nel.org/doc/man-pages/reporting_bugs.html .
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92IEEE/The Open Group                  2017                      TCSENDBREAK(3P)
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