getttyent.c revision 1573 
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 <ctype.h>
41#include <string.h>
42
43static char zapchar;
44static FILE *tf;
45
46struct ttyent *
47getttynam(tty)
48	const char *tty;
49{
50	register struct ttyent *t;
51
52	setttyent();
53	while (t = getttyent())
54		if (!strcmp(tty, t->ty_name))
55			break;
56	endttyent();
57	return (t);
58}
59
60struct ttyent *
61getttyent()
62{
63	static struct ttyent tty;
64	register int c;
65	register char *p;
66#define	MAXLINELENGTH	100
67	static char line[MAXLINELENGTH];
68	static char *skip(), *value();
69
70	if (!tf && !setttyent())
71		return (NULL);
72	for (;;) {
73		if (!fgets(p = line, sizeof(line), tf))
74			return (NULL);
75		/* skip lines that are too big */
76		if (!index(p, '\n')) {
77			while ((c = getc(tf)) != '\n' && c != EOF)
78				;
79			continue;
80		}
81		while (isspace(*p))
82			++p;
83		if (*p && *p != '#')
84			break;
85	}
86
87	zapchar = 0;
88	tty.ty_name = p;
89	p = skip(p);
90	if (!*(tty.ty_getty = p))
91		tty.ty_getty = tty.ty_type = NULL;
92	else {
93		p = skip(p);
94		if (!*(tty.ty_type = p))
95			tty.ty_type = NULL;
96		else
97			p = skip(p);
98	}
99	tty.ty_status = 0;
100	tty.ty_window = NULL;
101
102#define	scmp(e)	!strncmp(p, e, sizeof(e) - 1) && isspace(p[sizeof(e) - 1])
103#define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
104	for (; *p; p = skip(p)) {
105		if (scmp(_TTYS_OFF))
106			tty.ty_status &= ~TTY_ON;
107		else if (scmp(_TTYS_ON))
108			tty.ty_status |= TTY_ON;
109		else if (scmp(_TTYS_SECURE))
110			tty.ty_status |= TTY_SECURE;
111		else if (vcmp(_TTYS_WINDOW))
112			tty.ty_window = value(p);
113		else
114			break;
115	}
116
117	if (zapchar == '#' || *p == '#')
118		while ((c = *++p) == ' ' || c == '\t')
119			;
120	tty.ty_comment = p;
121	if (*p == 0)
122		tty.ty_comment = 0;
123	if (p = index(p, '\n'))
124		*p = '\0';
125	return (&tty);
126}
127
128#define	QUOTED	1
129
130/*
131 * Skip over the current field, removing quotes, and return a pointer to
132 * the next field.
133 */
134static char *
135skip(p)
136	register char *p;
137{
138	register char *t;
139	register int c, q;
140
141	for (q = 0, t = p; (c = *p) != '\0'; p++) {
142		if (c == '"') {
143			q ^= QUOTED;	/* obscure, but nice */
144			continue;
145		}
146		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
147			p++;
148		*t++ = *p;
149		if (q == QUOTED)
150			continue;
151		if (c == '#') {
152			zapchar = c;
153			*p = 0;
154			break;
155		}
156		if (c == '\t' || c == ' ' || c == '\n') {
157			zapchar = c;
158			*p++ = 0;
159			while ((c = *p) == '\t' || c == ' ' || c == '\n')
160				p++;
161			break;
162		}
163	}
164	*--t = '\0';
165	return (p);
166}
167
168static char *
169value(p)
170	register char *p;
171{
172
173	return ((p = index(p, '=')) ? ++p : NULL);
174}
175
176int
177setttyent()
178{
179
180	if (tf) {
181		(void)rewind(tf);
182		return (1);
183	} else if (tf = fopen(_PATH_TTYS, "r"))
184		return (1);
185	return (0);
186}
187
188int
189endttyent()
190{
191	int rval;
192
193	if (tf) {
194		rval = !(fclose(tf) == EOF);
195		tf = NULL;
196		return (rval);
197	}
198	return (1);
199}
200