1 | /* Copyright (C) 1991-2022 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU Lesser General Public |
6 | License as published by the Free Software Foundation; either |
7 | version 2.1 of the License, or (at your option) any later version. |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library; if not, see |
16 | <https://www.gnu.org/licenses/>. */ |
17 | |
18 | #include <errno.h> |
19 | #include <stddef.h> |
20 | #include <signal.h> |
21 | #include <termios.h> |
22 | #include <unistd.h> |
23 | #include "bsdtty.h" |
24 | #include <sys/file.h> |
25 | #include <sys/time.h> |
26 | #include <sys/types.h> |
27 | |
28 | /* Send zero bits on FD. */ |
29 | int |
30 | tcsendbreak (int fd, int duration) |
31 | { |
32 | struct timeval delay; |
33 | |
34 | /* The break lasts 0.25 to 0.5 seconds if DURATION is zero, |
35 | and an implementation-defined period if DURATION is nonzero. |
36 | We define a positive DURATION to be number of microseconds to break. */ |
37 | if (duration <= 0) |
38 | duration = 400000; |
39 | |
40 | delay.tv_sec = 0; |
41 | delay.tv_usec = duration; |
42 | |
43 | /* Starting sending break. */ |
44 | if (__ioctl (fd, TIOCSBRK, (void *) NULL) < 0) |
45 | return -1; |
46 | |
47 | /* Wait DURATION microseconds. */ |
48 | (void) __select (0, (fd_set *) NULL, (fd_set *) NULL, (fd_set *) NULL, |
49 | &delay); |
50 | |
51 | /* Turn off the break. */ |
52 | return __ioctl (fd, TIOCCBRK, (void *) NULL); |
53 | } |
54 | |