about summary refs log tree commit diff
path: root/sysdeps/unix/bsd/tcflow.c
blob: 1919d6d9eaaa18bef7c797b979ed9562ce5b5e26 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
/* Copyright (C) 1991, 1992, 1996 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#include <errno.h>
#include <stddef.h>
#include <termios.h>
#include <unistd.h>

#include "bsdtty.h"

/* Suspend or restart transmission on FD.  */
int
tcflow (fd, action)
     int fd;
     int action;
{
  switch (action)
    {
    case TCOOFF:
      return __ioctl (fd, TIOCSTOP, (PTR) NULL);
    case TCOON:
      return __ioctl (fd, TIOCSTART, (PTR) NULL);

    case TCIOFF:
    case TCION:
      {
	/* This just writes the START or STOP character with
	   `write'.  Is there another way to do this?  */
	struct termios attr;
	unsigned char c;
	if (tcgetattr (fd, &attr) < 0)
	  return -1;
	c = attr.c_cc[action == TCIOFF ? VSTOP : VSTART];
	if (c != _POSIX_VDISABLE && write (fd, &c, 1) < 1)
	  return -1;
	return 0;
      }

    default:
      __set_errno (EINVAL);
      return -1;
    }
}