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 <termios.h> |
21 | #include <unistd.h> |
22 | |
23 | #include "bsdtty.h" |
24 | |
25 | /* Suspend or restart transmission on FD. */ |
26 | int |
27 | tcflow (int fd, int action) |
28 | { |
29 | switch (action) |
30 | { |
31 | case TCOOFF: |
32 | return __ioctl (fd, TIOCSTOP, (void *) NULL); |
33 | case TCOON: |
34 | return __ioctl (fd, TIOCSTART, (void *) NULL); |
35 | |
36 | case TCIOFF: |
37 | case TCION: |
38 | { |
39 | /* This just writes the START or STOP character with |
40 | `write'. Is there another way to do this? */ |
41 | struct termios attr; |
42 | unsigned char c; |
43 | if (__tcgetattr (fd, &attr) < 0) |
44 | return -1; |
45 | c = attr.c_cc[action == TCIOFF ? VSTOP : VSTART]; |
46 | if (c != _POSIX_VDISABLE && write (fd, &c, 1) < 1) |
47 | return -1; |
48 | return 0; |
49 | } |
50 | |
51 | default: |
52 | __set_errno (EINVAL); |
53 | return -1; |
54 | } |
55 | } |
56 | |