getttyent.c revision 24899 
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)
35static char sccsid[] = "@(#)getttyent.c	8.1 (Berkeley) 6/4/93";
36#endif /* LIBC_SCCS and not lint */
37
38#include <ttyent.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <ctype.h>
42#include <string.h>
43
44static char zapchar;
45static FILE *tf;
46static size_t lbsize;
47static char *line;
48
49#define	MALLOCCHUNK	100
50
51static char *skip __P((char *));
52static char *value __P((char *));
53
54struct ttyent *
55getttynam(tty)
56	const char *tty;
57{
58	register struct ttyent *t;
59
60	if (strncmp(tty, "/dev/", 5) == 0)
61		tty += 5;
62	setttyent();
63	while ( (t = getttyent()) )
64		if (!strcmp(tty, t->ty_name))
65			break;
66	endttyent();
67	return (t);
68}
69
70struct ttyent *
71getttyent()
72{
73	static struct ttyent tty;
74	register char *p;
75	register int c;
76	size_t i;
77
78	if (!tf && !setttyent())
79		return (NULL);
80	for (;;) {
81		if (!fgets(p = line, lbsize, tf))
82			return (NULL);
83		/* extend buffer if line was too big, and retry */
84		while (!index(p, '\n')) {
85			i = strlen(p);
86			lbsize += MALLOCCHUNK;
87			if ((p = realloc(line, lbsize)) == NULL) {
88				(void)endttyent();
89				return (NULL);
90			}
91			line = p;
92			if (!fgets(&line[i], lbsize - i, tf))
93				return (NULL);
94		}
95		while (isspace(*p))
96			++p;
97		if (*p && *p != '#')
98			break;
99	}
100
101#define	scmp(e)	!strncmp(p, e, sizeof(e) - 1) && isspace(p[sizeof(e) - 1])
102#define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
103
104	zapchar = 0;
105	tty.ty_name = p;
106	p = skip(p);
107	if (!*(tty.ty_getty = p))
108		tty.ty_getty = tty.ty_type = NULL;
109	else {
110		p = skip(p);
111		if (!*(tty.ty_type = p))
112			tty.ty_type = NULL;
113		else {
114			/* compatibility kludge: handle network/dialup specially */
115			if (scmp(_TTYS_DIALUP))
116				tty.ty_status |= TTY_DIALUP;
117			else if (scmp(_TTYS_NETWORK))
118				tty.ty_status |= TTY_NETWORK;
119			p = skip(p);
120		}
121	}
122	tty.ty_status = 0;
123	tty.ty_window = NULL;
124	tty.ty_group  = _TTYS_NOGROUP;
125
126	for (; *p; p = skip(p)) {
127		if (scmp(_TTYS_OFF))
128			tty.ty_status &= ~TTY_ON;
129		else if (scmp(_TTYS_ON))
130			tty.ty_status |= TTY_ON;
131		else if (scmp(_TTYS_SECURE))
132			tty.ty_status |= TTY_SECURE;
133		else if (scmp(_TTYS_INSECURE))
134			tty.ty_status &= ~TTY_SECURE;
135		else if (scmp(_TTYS_DIALUP))
136			tty.ty_status |= TTY_DIALUP;
137		else if (scmp(_TTYS_NETWORK))
138			tty.ty_status |= TTY_NETWORK;
139		else if (vcmp(_TTYS_WINDOW))
140			tty.ty_window = value(p);
141		else if (vcmp(_TTYS_GROUP))
142			tty.ty_group = value(p);
143		else
144			break;
145	}
146
147	if (zapchar == '#' || *p == '#')
148		while ((c = *++p) == ' ' || c == '\t')
149			;
150	tty.ty_comment = p;
151	if (*p == 0)
152		tty.ty_comment = 0;
153	if ( (p = index(p, '\n')) )
154		*p = '\0';
155	return (&tty);
156}
157
158#define	QUOTED	1
159
160/*
161 * Skip over the current field, removing quotes, and return a pointer to
162 * the next field.
163 */
164static char *
165skip(p)
166	register char *p;
167{
168	register char *t;
169	register int c, q;
170
171	for (q = 0, t = p; (c = *p) != '\0'; p++) {
172		if (c == '"') {
173			q ^= QUOTED;	/* obscure, but nice */
174			continue;
175		}
176		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
177			p++;
178		*t++ = *p;
179		if (q == QUOTED)
180			continue;
181		if (c == '#') {
182			zapchar = c;
183			*p = 0;
184			break;
185		}
186		if (c == '\t' || c == ' ' || c == '\n') {
187			zapchar = c;
188			*p++ = 0;
189			while ((c = *p) == '\t' || c == ' ' || c == '\n')
190				p++;
191			break;
192		}
193	}
194	*--t = '\0';
195	return (p);
196}
197
198static char *
199value(p)
200	register char *p;
201{
202
203	return ((p = index(p, '=')) ? ++p : NULL);
204}
205
206int
207setttyent()
208{
209
210	if (line == NULL) {
211		if ((line = malloc(MALLOCCHUNK)) == NULL)
212			return (0);
213		lbsize = MALLOCCHUNK;
214	}
215	if (tf) {
216		rewind(tf);
217		return (1);
218	} else if ( (tf = fopen(_PATH_TTYS, "r")) )
219		return (1);
220	return (0);
221}
222
223int
224endttyent()
225{
226	int rval;
227
228	/*
229         * NB: Don't free `line' because getttynam()
230	 * may still be referencing it
231	 */
232	if (tf) {
233		rval = (fclose(tf) != EOF);
234		tf = NULL;
235		return (rval);
236	}
237	return (1);
238}
239
240static int
241isttystat(tty, flag)
242	const char *tty;
243	int flag;
244{
245	register struct ttyent *t;
246
247	return ((t = getttynam(tty)) == NULL) ? 0 : !!(t->ty_status & flag);
248}
249
250
251int
252isdialuptty(tty)
253	const char *tty;
254{
255
256	return isttystat(tty, TTY_DIALUP);
257}
258
259int isnettty(tty)
260	const char *tty;
261{
262
263	return isttystat(tty, TTY_NETWORK);
264}
265