1 /*
2  * Copyright (c) 1988, 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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)ttyslot.c	8.1 (Berkeley) 6/4/93";
32 #endif /* LIBC_SCCS and not lint */
33 
34 #include <ttyent.h>
35 #include <alloca.h>
36 #include <stdio.h>
37 #include <string.h>
38 #include <unistd.h>
39 
40 int
ttyslot(void)41 ttyslot (void)
42 {
43 	struct ttyent *ttyp;
44 	int slot;
45 	char *p;
46 	int cnt;
47 	size_t buflen = __sysconf (_SC_TTY_NAME_MAX) + 1;
48 	char *name;
49 
50 	if (buflen == 0)
51 	  /* This should be enough if no fixed value is given.  */
52 	  buflen = 32;
53 
54 	name = __alloca (buflen);
55 
56 	__setttyent();
57 	for (cnt = 0; cnt < 3; ++cnt)
58 		if (__ttyname_r (cnt, name, buflen) == 0) {
59 			if ((p = strrchr (name, '/')))
60 				++p;
61 			else
62 				p = name;
63 			for (slot = 1; (ttyp = __getttyent()); ++slot)
64 				if (!strcmp(ttyp->ty_name, p)) {
65 					__endttyent();
66 					return(slot);
67 				}
68 			break;
69 		}
70 	__endttyent();
71 	return(0);
72 }
73