getttyent.c revision 1.8 
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. 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)
31static char rcsid[] = "$OpenBSD: getttyent.c,v 1.8 2005/03/25 15:38:47 otto Exp $";
32#endif /* LIBC_SCCS and not lint */
33
34#include <ttyent.h>
35#include <stdio.h>
36#include <ctype.h>
37#include <string.h>
38
39static char zapchar;
40static FILE *tf;
41
42static char *skip(char *);
43static char *value(char *);
44
45struct ttyent *
46getttynam(const char *tty)
47{
48	struct ttyent *t;
49
50	setttyent();
51	while ((t = getttyent()))
52		if (!strcmp(tty, t->ty_name))
53			break;
54	endttyent();
55	return (t);
56}
57
58struct ttyent *
59getttyent(void)
60{
61	static struct ttyent tty;
62	int c;
63	char *p;
64#define	MAXLINELENGTH	200
65	static char line[MAXLINELENGTH];
66
67	if (!tf && !setttyent())
68		return (NULL);
69	for (;;) {
70		if (!fgets(p = line, sizeof(line), tf))
71			return (NULL);
72		/* skip lines that are too big */
73		if (!strchr(p, '\n')) {
74			while ((c = getc(tf)) != '\n' && c != EOF)
75				;
76			continue;
77		}
78		while (isspace(*p))
79			++p;
80		if (*p && *p != '#')
81			break;
82	}
83
84	zapchar = 0;
85	tty.ty_name = p;
86	p = skip(p);
87	if (!*(tty.ty_getty = p))
88		tty.ty_getty = tty.ty_type = NULL;
89	else {
90		p = skip(p);
91		if (!*(tty.ty_type = p))
92			tty.ty_type = NULL;
93		else
94			p = skip(p);
95	}
96	tty.ty_status = 0;
97	tty.ty_window = NULL;
98
99#define	scmp(e)	!strncmp(p, e, sizeof(e) - 1) && isspace(p[sizeof(e) - 1])
100#define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
101	for (; *p; p = skip(p)) {
102		if (scmp(_TTYS_OFF))
103			tty.ty_status &= ~TTY_ON;
104		else if (scmp(_TTYS_ON))
105			tty.ty_status |= TTY_ON;
106		else if (scmp(_TTYS_SECURE))
107			tty.ty_status |= TTY_SECURE;
108		else if (scmp(_TTYS_LOCAL))
109			tty.ty_status |= TTY_LOCAL;
110		else if (scmp(_TTYS_RTSCTS))
111			tty.ty_status |= TTY_RTSCTS;
112		else if (scmp(_TTYS_SOFTCAR))
113			tty.ty_status |= TTY_SOFTCAR;
114		else if (scmp(_TTYS_MDMBUF))
115			tty.ty_status |= TTY_MDMBUF;
116		else if (vcmp(_TTYS_WINDOW))
117			tty.ty_window = value(p);
118		else
119			break;
120	}
121
122	if (zapchar == '#' || *p == '#')
123		while ((c = *++p) == ' ' || c == '\t')
124			;
125	tty.ty_comment = p;
126	if (*p == 0)
127		tty.ty_comment = 0;
128	if ((p = strchr(p, '\n')))
129		*p = '\0';
130	return (&tty);
131}
132
133#define	QUOTED	1
134
135/*
136 * Skip over the current field, removing quotes, and return a pointer to
137 * the next field.
138 */
139static char *
140skip(char *p)
141{
142	char *t;
143	int c, q;
144
145	for (q = 0, t = p; (c = *p) != '\0'; p++) {
146		if (c == '"') {
147			q ^= QUOTED;	/* obscure, but nice */
148			continue;
149		}
150		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
151			p++;
152		*t++ = *p;
153		if (q == QUOTED)
154			continue;
155		if (c == '#') {
156			zapchar = c;
157			*p = 0;
158			break;
159		}
160		if (c == '\t' || c == ' ' || c == '\n') {
161			zapchar = c;
162			*p++ = 0;
163			while ((c = *p) == '\t' || c == ' ' || c == '\n')
164				p++;
165			break;
166		}
167	}
168	*--t = '\0';
169	return (p);
170}
171
172static char *
173value(char *p)
174{
175
176	return ((p = strchr(p, '=')) ? ++p : NULL);
177}
178
179int
180setttyent(void)
181{
182
183	if (tf) {
184		rewind(tf);
185		return (1);
186	} else if ((tf = fopen(_PATH_TTYS, "r")))
187		return (1);
188	return (0);
189}
190
191int
192endttyent(void)
193{
194	int rval;
195
196	if (tf) {
197		rval = !(fclose(tf) == EOF);
198		tf = NULL;
199		return (rval);
200	}
201	return (1);
202}
203