/* Send break to terminal.

   Copyright (C) 1996-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <errno.h>

#include <stddef.h>

#include <termios.h>

#include <sys/ioctl.h>

/* Send zero bits on FD.  */

int

tcsendbreak (int fd, int duration)

{

  /* The break lasts 0.25 to 0.5 seconds if DURATION is zero,

     and an implementation-defined period if DURATION is nonzero.

     We define a positive DURATION to be number of milliseconds to break.  */

  if (duration <= 0)

    return __ioctl (fd, TCSBRK, 0);

#ifdef TCSBRKP

  /* Probably Linux-specific: a positive third TCSBRKP ioctl argument is

     defined to be the number of 100ms units to break.  */

  return __ioctl (fd, TCSBRKP, (duration + 99) / 100);

#else

  /* ioctl can't send a break of any other duration for us.

     This could be changed to use trickery (e.g. lower speed and

     send a '\0') to send the break, but for now just return an error.  */

  return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);

#endif

}