45 lines
1.7 KiB
C
45 lines
1.7 KiB
C
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/* Send break to terminal.
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Copyright (C) 1996-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <errno.h>
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#include <stddef.h>
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#include <termios.h>
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#include <sys/ioctl.h>
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/* Send zero bits on FD. */
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int
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tcsendbreak (int fd, int duration)
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{
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/* The break lasts 0.25 to 0.5 seconds if DURATION is zero,
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and an implementation-defined period if DURATION is nonzero.
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We define a positive DURATION to be number of milliseconds to break. */
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if (duration <= 0)
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return __ioctl (fd, TCSBRK, 0);
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#ifdef TCSBRKP
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/* Probably Linux-specific: a positive third TCSBRKP ioctl argument is
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defined to be the number of 100ms units to break. */
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return __ioctl (fd, TCSBRKP, (duration + 99) / 100);
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#else
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/* ioctl can't send a break of any other duration for us.
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This could be changed to use trickery (e.g. lower speed and
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send a '\0') to send the break, but for now just return an error. */
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return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);
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#endif
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}
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