glibc/sysdeps/unix/bsd/tcflow.c

56 lines
1.5 KiB
C

/* Copyright (C) 1991-2020 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
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <stddef.h>
#include <termios.h>
#include <unistd.h>
#include "bsdtty.h"
/* Suspend or restart transmission on FD. */
int
tcflow (int fd, int action)
{
switch (action)
{
case TCOOFF:
return __ioctl (fd, TIOCSTOP, (void *) NULL);
case TCOON:
return __ioctl (fd, TIOCSTART, (void *) 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;
}
}