xref: /netbsd-src/lib/libc/gen/getttyent.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: getttyent.c,v 1.21 2004/11/10 23:59:06 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char sccsid[] = "@(#)getttyent.c	8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: getttyent.c,v 1.21 2004/11/10 23:59:06 christos Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40 
41 #include "namespace.h"
42 
43 #include <assert.h>
44 #include <ctype.h>
45 #include <stdio.h>
46 #include <string.h>
47 #include <ttyent.h>
48 #include <errno.h>
49 #include <err.h>
50 #include <stdlib.h>
51 
52 #ifdef __weak_alias
53 __weak_alias(endttyent,_endttyent)
54 __weak_alias(getttyent,_getttyent)
55 __weak_alias(getttynam,_getttynam)
56 __weak_alias(setttyent,_setttyent)
57 #endif
58 
59 static FILE *tf;
60 static size_t lineno = 0;
61 static char *skip(char *, char *);
62 static char *value(char *);
63 
64 struct ttyent *
65 getttynam(const char *tty)
66 {
67 	struct ttyent *t;
68 
69 	_DIAGASSERT(tty != NULL);
70 
71 	setttyent();
72 	while ((t = getttyent()) != NULL)
73 		if (!strcmp(tty, t->ty_name))
74 			break;
75 	endttyent();
76 	return (t);
77 }
78 
79 struct ttyent *
80 getttyent(void)
81 {
82 	static struct ttyent tty;
83 	int c;
84 	char *p;
85 	size_t len;
86 	static char *line = NULL;
87 	char zapchar;
88 
89 	if (line)
90 		free(line);
91 
92 	if (!tf && !setttyent())
93 		return NULL;
94 
95 	for (;;) {
96 		errno = 0;
97 		line = fparseln(tf, &len, &lineno, NULL, FPARSELN_UNESCALL);
98 		if (line == NULL) {
99 			if (errno != 0)
100 				warn(__func__);
101 			return NULL;
102 		}
103 		for (p = line; *p && isspace((unsigned char)*p); p++)
104 			continue;
105 		if (*p && *p != '#')
106 			break;
107 		free(line);
108 	}
109 
110 	tty.ty_name = p;
111 	p = skip(p, &zapchar);
112 	if (*(tty.ty_getty = p) == '\0')
113 		tty.ty_getty = tty.ty_type = NULL;
114 	else {
115 		p = skip(p, &zapchar);
116 		if (*(tty.ty_type = p) == '\0')
117 			tty.ty_type = NULL;
118 		else
119 			p = skip(p, &zapchar);
120 	}
121 	tty.ty_status = 0;
122 	tty.ty_window = NULL;
123 
124 #define	scmp(e)	!strncmp(p, e, sizeof(e) - 1) && (isspace((unsigned char) p[sizeof(e) - 1]) || p[sizeof(e) - 1] == '\0')
125 #define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
126 	for (; *p; p = skip(p, &zapchar)) {
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_LOCAL))
134 			tty.ty_status |= TTY_LOCAL;
135 		else if (scmp(_TTYS_RTSCTS))
136 			tty.ty_status |= TTY_RTSCTS;
137 		else if (scmp(_TTYS_DTRCTS))
138 			tty.ty_status |= TTY_DTRCTS;
139 		else if (scmp(_TTYS_SOFTCAR))
140 			tty.ty_status |= TTY_SOFTCAR;
141 		else if (scmp(_TTYS_MDMBUF))
142 			tty.ty_status |= TTY_MDMBUF;
143 		else if (vcmp(_TTYS_WINDOW))
144 			tty.ty_window = value(p);
145 		else if (vcmp(_TTYS_CLASS))
146 			tty.ty_class = value(p);
147 		else
148 			warnx("%s: %s, %lu: unknown option `%s'",
149 			    __func__, _PATH_TTYS, (unsigned long)lineno, p);
150 	}
151 
152 	if (zapchar == '#' || *p == '#')
153 		while ((c = *++p) == ' ' || c == '\t')
154 			continue;
155 	tty.ty_comment = p;
156 	if (*p == '\0')
157 		tty.ty_comment = NULL;
158 	if ((p = strchr(p, '\n')) != NULL)
159 		*p = '\0';
160 	return &tty;
161 }
162 
163 #define	QUOTED	1
164 
165 /*
166  * Skip over the current field, removing quotes, and return a pointer to
167  * the next field.
168  */
169 static char *
170 skip(char *p, char *zapchar)
171 {
172 	char *t;
173 	int c, q;
174 
175 	_DIAGASSERT(p != NULL);
176 	*zapchar = '\0';
177 
178 	for (q = 0, t = p; (c = *p) != '\0'; p++) {
179 		if (c == '"') {
180 			q ^= QUOTED;	/* obscure, but nice */
181 			continue;
182 		}
183 		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
184 			p++;
185 		*t++ = *p;
186 		if (q == QUOTED)
187 			continue;
188 		if (c == '#') {
189 			*zapchar = c;
190 			*p = '\0';
191 			*--t = '\0';
192 			return p;
193 		}
194 		if (c == '\t' || c == ' ' || c == '\n') {
195 			*zapchar = c;
196 			*p++ = '\0';
197 			while ((c = *p) == '\t' || c == ' ' || c == '\n')
198 				p++;
199 			*--t = '\0';
200 			return p;
201 		}
202 	}
203 	if (t != p)
204 		*t = '\0';
205 	return p;
206 }
207 
208 static char *
209 value(char *p)
210 {
211 
212 	_DIAGASSERT(p != NULL);
213 
214 	return (p = strchr(p, '=')) != NULL ? ++p : NULL;
215 }
216 
217 int
218 setttyent(void)
219 {
220 	lineno = 0;
221 	if (tf) {
222 		rewind(tf);
223 		return 1;
224 	} else if ((tf = fopen(_PATH_TTYS, "r")) != NULL)
225 		return 1;
226 	return 0;
227 }
228 
229 int
230 endttyent(void)
231 {
232 	int rval;
233 
234 	if (tf) {
235 		rval = !(fclose(tf) == EOF);
236 		tf = NULL;
237 		return rval;
238 	}
239 	return 1;
240 }
241