/* Send break to terminal. Copyright (C) 1996-2014 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. */ __set_errno (EINVAL); return -1; #endif }