xref: /netbsd/lib/libc/termios/tcflow.c (revision 6550d01e)
1 /*	$NetBSD: tcflow.c,v 1.8 2003/08/07 16:44:13 agc Exp $	*/
2 
3 /*-
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char sccsid[] = "@(#)termios.c	8.2 (Berkeley) 2/21/94";
36 #else
37 __RCSID("$NetBSD: tcflow.c,v 1.8 2003/08/07 16:44:13 agc Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40 
41 #include "namespace.h"
42 #include <sys/ioctl.h>
43 
44 #include <assert.h>
45 #include <errno.h>
46 #include <termios.h>
47 #include <unistd.h>
48 
49 #ifdef __weak_alias
50 __weak_alias(tcflow,_tcflow)
51 #endif
52 
53 int
54 tcflow(fd, action)
55 	int fd, action;
56 {
57 	struct termios term;
58 	u_char c;
59 
60 	_DIAGASSERT(fd != -1);
61 
62 	switch (action) {
63 	case TCOOFF:
64 		return (ioctl(fd, TIOCSTOP, 0));
65 	case TCOON:
66 		return (ioctl(fd, TIOCSTART, 0));
67 	case TCION:
68 	case TCIOFF:
69 		if (tcgetattr(fd, &term) == -1)
70 			return (-1);
71 		c = term.c_cc[action == TCIOFF ? VSTOP : VSTART];
72 		if (c != _POSIX_VDISABLE && write(fd, &c, sizeof(c)) == -1)
73 			return (-1);
74 		return (0);
75 	default:
76 		errno = EINVAL;
77 		return (-1);
78 	}
79 	/* NOTREACHED */
80 }
81