xref: /openbsd-src/lib/libc/termios/tcflow.c (revision e9b2b68ca3a6cce2632b4a73cc801bbb6f19c001)
1 /*-
2  * Copyright (c) 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char rcsid[] = "$OpenBSD: tcflow.c,v 1.2 1996/08/19 08:34:38 tholo Exp $";
36 #endif /* LIBC_SCCS and not lint */
37 
38 #include <sys/ioctl.h>
39 #include <termios.h>
40 #include <unistd.h>
41 #include <errno.h>
42 
43 int
44 tcflow(fd, action)
45 	int fd, action;
46 {
47 	struct termios term;
48 	u_char c;
49 
50 	switch (action) {
51 	case TCOOFF:
52 		return (ioctl(fd, TIOCSTOP, 0));
53 	case TCOON:
54 		return (ioctl(fd, TIOCSTART, 0));
55 	case TCION:
56 	case TCIOFF:
57 		if (tcgetattr(fd, &term) == -1)
58 			return (-1);
59 		c = term.c_cc[action == TCIOFF ? VSTOP : VSTART];
60 		if (c != _POSIX_VDISABLE && write(fd, &c, sizeof(c)) == -1)
61 			return (-1);
62 		return (0);
63 	default:
64 		errno = EINVAL;
65 		return (-1);
66 	}
67 	/* NOTREACHED */
68 }
69