glibc/sysdeps/unix/bsd/tcsendbrk.c

56 lines
1.7 KiB
C

/* Copyright (C) 1991-2015 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 <signal.h>
#include <termios.h>
#include <unistd.h>
#include "bsdtty.h"
#include <sys/file.h>
#include <sys/time.h>
#include <sys/types.h>
/* Send zero bits on FD. */
int
tcsendbreak (fd, duration)
int fd;
int duration;
{
struct timeval delay;
/* 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 microseconds to break. */
if (duration <= 0)
duration = 400000;
delay.tv_sec = 0;
delay.tv_usec = duration;
/* Starting sending break. */
if (__ioctl (fd, TIOCSBRK, (void *) NULL) < 0)
return -1;
/* Wait DURATION microseconds. */
(void) __select (0, (fd_set *) NULL, (fd_set *) NULL, (fd_set *) NULL,
&delay);
/* Turn off the break. */
return __ioctl (fd, TIOCCBRK, (void *) NULL);
}