xref: /freebsd/lib/libc/gen/getttyent.c (revision a14a0223ae1b172e96dd2a1d849e22026a98b692)
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  * $FreeBSD$
34  */
35 
36 #if defined(LIBC_SCCS) && !defined(lint)
37 static char sccsid[] = "@(#)getttyent.c	8.1 (Berkeley) 6/4/93";
38 #endif /* LIBC_SCCS and not lint */
39 
40 #include <ttyent.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <ctype.h>
44 #include <string.h>
45 
46 static char zapchar;
47 static FILE *tf;
48 static size_t lbsize;
49 static char *line;
50 
51 #define	MALLOCCHUNK	100
52 
53 static char *skip __P((char *));
54 static char *value __P((char *));
55 
56 struct ttyent *
57 getttynam(tty)
58 	const char *tty;
59 {
60 	register struct ttyent *t;
61 
62 	if (strncmp(tty, "/dev/", 5) == 0)
63 		tty += 5;
64 	setttyent();
65 	while ( (t = getttyent()) )
66 		if (!strcmp(tty, t->ty_name))
67 			break;
68 	endttyent();
69 	return (t);
70 }
71 
72 struct ttyent *
73 getttyent()
74 {
75 	static struct ttyent tty;
76 	register char *p;
77 	register int c;
78 	size_t i;
79 
80 	if (!tf && !setttyent())
81 		return (NULL);
82 	for (;;) {
83 		if (!fgets(p = line, lbsize, tf))
84 			return (NULL);
85 		/* extend buffer if line was too big, and retry */
86 		while (!index(p, '\n')) {
87 			i = strlen(p);
88 			lbsize += MALLOCCHUNK;
89 			if ((p = realloc(line, lbsize)) == NULL) {
90 				(void)endttyent();
91 				return (NULL);
92 			}
93 			line = p;
94 			if (!fgets(&line[i], lbsize - i, tf))
95 				return (NULL);
96 		}
97 		while (isspace((unsigned char)*p))
98 			++p;
99 		if (*p && *p != '#')
100 			break;
101 	}
102 
103 #define scmp(e) !strncmp(p, e, sizeof(e) - 1) && isspace((unsigned char)p[sizeof(e) - 1])
104 #define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
105 
106 	zapchar = 0;
107 	tty.ty_name = p;
108 	p = skip(p);
109 	if (!*(tty.ty_getty = p))
110 		tty.ty_getty = tty.ty_type = NULL;
111 	else {
112 		p = skip(p);
113 		if (!*(tty.ty_type = p))
114 			tty.ty_type = NULL;
115 		else {
116 			/* compatibility kludge: handle network/dialup specially */
117 			if (scmp(_TTYS_DIALUP))
118 				tty.ty_status |= TTY_DIALUP;
119 			else if (scmp(_TTYS_NETWORK))
120 				tty.ty_status |= TTY_NETWORK;
121 			p = skip(p);
122 		}
123 	}
124 	tty.ty_status = 0;
125 	tty.ty_window = NULL;
126 	tty.ty_group  = _TTYS_NOGROUP;
127 
128 	for (; *p; p = skip(p)) {
129 		if (scmp(_TTYS_OFF))
130 			tty.ty_status &= ~TTY_ON;
131 		else if (scmp(_TTYS_ON))
132 			tty.ty_status |= TTY_ON;
133 		else if (scmp(_TTYS_SECURE))
134 			tty.ty_status |= TTY_SECURE;
135 		else if (scmp(_TTYS_INSECURE))
136 			tty.ty_status &= ~TTY_SECURE;
137 		else if (scmp(_TTYS_DIALUP))
138 			tty.ty_status |= TTY_DIALUP;
139 		else if (scmp(_TTYS_NETWORK))
140 			tty.ty_status |= TTY_NETWORK;
141 		else if (vcmp(_TTYS_WINDOW))
142 			tty.ty_window = value(p);
143 		else if (vcmp(_TTYS_GROUP))
144 			tty.ty_group = value(p);
145 		else
146 			break;
147 	}
148 
149 	if (zapchar == '#' || *p == '#')
150 		while ((c = *++p) == ' ' || c == '\t')
151 			;
152 	tty.ty_comment = p;
153 	if (*p == 0)
154 		tty.ty_comment = 0;
155 	if ( (p = index(p, '\n')) )
156 		*p = '\0';
157 	return (&tty);
158 }
159 
160 #define	QUOTED	1
161 
162 /*
163  * Skip over the current field, removing quotes, and return a pointer to
164  * the next field.
165  */
166 static char *
167 skip(p)
168 	register char *p;
169 {
170 	register char *t;
171 	register int c, q;
172 
173 	for (q = 0, t = p; (c = *p) != '\0'; p++) {
174 		if (c == '"') {
175 			q ^= QUOTED;	/* obscure, but nice */
176 			continue;
177 		}
178 		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
179 			p++;
180 		*t++ = *p;
181 		if (q == QUOTED)
182 			continue;
183 		if (c == '#') {
184 			zapchar = c;
185 			*p = 0;
186 			break;
187 		}
188 		if (c == '\t' || c == ' ' || c == '\n') {
189 			zapchar = c;
190 			*p++ = 0;
191 			while ((c = *p) == '\t' || c == ' ' || c == '\n')
192 				p++;
193 			break;
194 		}
195 	}
196 	*--t = '\0';
197 	return (p);
198 }
199 
200 static char *
201 value(p)
202 	register char *p;
203 {
204 
205 	return ((p = index(p, '=')) ? ++p : NULL);
206 }
207 
208 int
209 setttyent()
210 {
211 
212 	if (line == NULL) {
213 		if ((line = malloc(MALLOCCHUNK)) == NULL)
214 			return (0);
215 		lbsize = MALLOCCHUNK;
216 	}
217 	if (tf) {
218 		rewind(tf);
219 		return (1);
220 	} else if ( (tf = fopen(_PATH_TTYS, "r")) )
221 		return (1);
222 	return (0);
223 }
224 
225 int
226 endttyent()
227 {
228 	int rval;
229 
230 	/*
231          * NB: Don't free `line' because getttynam()
232 	 * may still be referencing it
233 	 */
234 	if (tf) {
235 		rval = (fclose(tf) != EOF);
236 		tf = NULL;
237 		return (rval);
238 	}
239 	return (1);
240 }
241 
242 static int
243 isttystat(tty, flag)
244 	const char *tty;
245 	int flag;
246 {
247 	register struct ttyent *t;
248 
249 	return ((t = getttynam(tty)) == NULL) ? 0 : !!(t->ty_status & flag);
250 }
251 
252 
253 int
254 isdialuptty(tty)
255 	const char *tty;
256 {
257 
258 	return isttystat(tty, TTY_DIALUP);
259 }
260 
261 int isnettty(tty)
262 	const char *tty;
263 {
264 
265 	return isttystat(tty, TTY_NETWORK);
266 }
267