tty.c revision 1.9 
1/*	$OpenBSD: tty.c,v 1.9 2006/03/14 22:08:01 deraadt Exp $	*/
2
3#include "sh.h"
4#include <sys/stat.h>
5#define EXTERN
6#include "tty.h"
7#undef EXTERN
8
9/* Initialize tty_fd.  Used for saving/reseting tty modes upon
10 * foreground job completion and for setting up tty process group.
11 */
12void
13tty_init(int init_ttystate)
14{
15	int	do_close = 1;
16	int	tfd;
17
18	if (tty_fd >= 0) {
19		close(tty_fd);
20		tty_fd = -1;
21	}
22	tty_devtty = 1;
23
24	if ((tfd = open("/dev/tty", O_RDWR, 0)) < 0) {
25		tty_devtty = 0;
26		warningf(false, "No controlling tty (open /dev/tty: %s)",
27		    strerror(errno));
28	}
29
30	if (tfd < 0) {
31		do_close = 0;
32		if (isatty(0))
33			tfd = 0;
34		else if (isatty(2))
35			tfd = 2;
36		else {
37			warningf(false, "Can't find tty file descriptor");
38			return;
39		}
40	}
41	if ((tty_fd = fcntl(tfd, F_DUPFD, FDBASE)) < 0) {
42		warningf(false, "j_ttyinit: dup of tty fd failed: %s",
43		    strerror(errno));
44	} else if (fcntl(tty_fd, F_SETFD, FD_CLOEXEC) < 0) {
45		warningf(false, "j_ttyinit: can't set close-on-exec flag: %s",
46		    strerror(errno));
47		close(tty_fd);
48		tty_fd = -1;
49	} else if (init_ttystate)
50		tcgetattr(tty_fd, &tty_state);
51	if (do_close)
52		close(tfd);
53}
54
55void
56tty_close(void)
57{
58	if (tty_fd >= 0) {
59		close(tty_fd);
60		tty_fd = -1;
61	}
62}
63