getttyent.c revision 1.9 
1/*	$OpenBSD: getttyent.c,v 1.9 2005/08/08 08:05:34 espie Exp $ */
2/*
3 * Copyright (c) 1989, 1993
4 *	The Regents of the University of California.  All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 *    may be used to endorse or promote products derived from this software
16 *    without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <ttyent.h>
32#include <stdio.h>
33#include <ctype.h>
34#include <string.h>
35
36static char zapchar;
37static FILE *tf;
38
39static char *skip(char *);
40static char *value(char *);
41
42struct ttyent *
43getttynam(const char *tty)
44{
45	struct ttyent *t;
46
47	setttyent();
48	while ((t = getttyent()))
49		if (!strcmp(tty, t->ty_name))
50			break;
51	endttyent();
52	return (t);
53}
54
55struct ttyent *
56getttyent(void)
57{
58	static struct ttyent tty;
59	int c;
60	char *p;
61#define	MAXLINELENGTH	200
62	static char line[MAXLINELENGTH];
63
64	if (!tf && !setttyent())
65		return (NULL);
66	for (;;) {
67		if (!fgets(p = line, sizeof(line), tf))
68			return (NULL);
69		/* skip lines that are too big */
70		if (!strchr(p, '\n')) {
71			while ((c = getc(tf)) != '\n' && c != EOF)
72				;
73			continue;
74		}
75		while (isspace(*p))
76			++p;
77		if (*p && *p != '#')
78			break;
79	}
80
81	zapchar = 0;
82	tty.ty_name = p;
83	p = skip(p);
84	if (!*(tty.ty_getty = p))
85		tty.ty_getty = tty.ty_type = NULL;
86	else {
87		p = skip(p);
88		if (!*(tty.ty_type = p))
89			tty.ty_type = NULL;
90		else
91			p = skip(p);
92	}
93	tty.ty_status = 0;
94	tty.ty_window = NULL;
95
96#define	scmp(e)	!strncmp(p, e, sizeof(e) - 1) && isspace(p[sizeof(e) - 1])
97#define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
98	for (; *p; p = skip(p)) {
99		if (scmp(_TTYS_OFF))
100			tty.ty_status &= ~TTY_ON;
101		else if (scmp(_TTYS_ON))
102			tty.ty_status |= TTY_ON;
103		else if (scmp(_TTYS_SECURE))
104			tty.ty_status |= TTY_SECURE;
105		else if (scmp(_TTYS_LOCAL))
106			tty.ty_status |= TTY_LOCAL;
107		else if (scmp(_TTYS_RTSCTS))
108			tty.ty_status |= TTY_RTSCTS;
109		else if (scmp(_TTYS_SOFTCAR))
110			tty.ty_status |= TTY_SOFTCAR;
111		else if (scmp(_TTYS_MDMBUF))
112			tty.ty_status |= TTY_MDMBUF;
113		else if (vcmp(_TTYS_WINDOW))
114			tty.ty_window = value(p);
115		else
116			break;
117	}
118
119	if (zapchar == '#' || *p == '#')
120		while ((c = *++p) == ' ' || c == '\t')
121			;
122	tty.ty_comment = p;
123	if (*p == 0)
124		tty.ty_comment = 0;
125	if ((p = strchr(p, '\n')))
126		*p = '\0';
127	return (&tty);
128}
129
130#define	QUOTED	1
131
132/*
133 * Skip over the current field, removing quotes, and return a pointer to
134 * the next field.
135 */
136static char *
137skip(char *p)
138{
139	char *t;
140	int c, q;
141
142	for (q = 0, t = p; (c = *p) != '\0'; p++) {
143		if (c == '"') {
144			q ^= QUOTED;	/* obscure, but nice */
145			continue;
146		}
147		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
148			p++;
149		*t++ = *p;
150		if (q == QUOTED)
151			continue;
152		if (c == '#') {
153			zapchar = c;
154			*p = 0;
155			break;
156		}
157		if (c == '\t' || c == ' ' || c == '\n') {
158			zapchar = c;
159			*p++ = 0;
160			while ((c = *p) == '\t' || c == ' ' || c == '\n')
161				p++;
162			break;
163		}
164	}
165	*--t = '\0';
166	return (p);
167}
168
169static char *
170value(char *p)
171{
172
173	return ((p = strchr(p, '=')) ? ++p : NULL);
174}
175
176int
177setttyent(void)
178{
179
180	if (tf) {
181		rewind(tf);
182		return (1);
183	} else if ((tf = fopen(_PATH_TTYS, "r")))
184		return (1);
185	return (0);
186}
187
188int
189endttyent(void)
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