xref: /freebsd/lib/libc/gen/getttyent.c (revision 4cf49a43559ed9fdad601bdcccd2c55963008675)
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)
35 static 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 <stdlib.h>
41 #include <ctype.h>
42 #include <string.h>
43 
44 static char zapchar;
45 static FILE *tf;
46 static size_t lbsize;
47 static char *line;
48 
49 #define	MALLOCCHUNK	100
50 
51 static char *skip __P((char *));
52 static char *value __P((char *));
53 
54 struct ttyent *
55 getttynam(tty)
56 	const char *tty;
57 {
58 	register struct ttyent *t;
59 
60 	if (strncmp(tty, "/dev/", 5) == 0)
61 		tty += 5;
62 	setttyent();
63 	while ( (t = getttyent()) )
64 		if (!strcmp(tty, t->ty_name))
65 			break;
66 	endttyent();
67 	return (t);
68 }
69 
70 struct ttyent *
71 getttyent()
72 {
73 	static struct ttyent tty;
74 	register char *p;
75 	register int c;
76 	size_t i;
77 
78 	if (!tf && !setttyent())
79 		return (NULL);
80 	for (;;) {
81 		if (!fgets(p = line, lbsize, tf))
82 			return (NULL);
83 		/* extend buffer if line was too big, and retry */
84 		while (!index(p, '\n')) {
85 			i = strlen(p);
86 			lbsize += MALLOCCHUNK;
87 			if ((p = realloc(line, lbsize)) == NULL) {
88 				(void)endttyent();
89 				return (NULL);
90 			}
91 			line = p;
92 			if (!fgets(&line[i], lbsize - i, tf))
93 				return (NULL);
94 		}
95 		while (isspace(*p))
96 			++p;
97 		if (*p && *p != '#')
98 			break;
99 	}
100 
101 #define	scmp(e)	!strncmp(p, e, sizeof(e) - 1) && isspace(p[sizeof(e) - 1])
102 #define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
103 
104 	zapchar = 0;
105 	tty.ty_name = p;
106 	p = skip(p);
107 	if (!*(tty.ty_getty = p))
108 		tty.ty_getty = tty.ty_type = NULL;
109 	else {
110 		p = skip(p);
111 		if (!*(tty.ty_type = p))
112 			tty.ty_type = NULL;
113 		else {
114 			/* compatibility kludge: handle network/dialup specially */
115 			if (scmp(_TTYS_DIALUP))
116 				tty.ty_status |= TTY_DIALUP;
117 			else if (scmp(_TTYS_NETWORK))
118 				tty.ty_status |= TTY_NETWORK;
119 			p = skip(p);
120 		}
121 	}
122 	tty.ty_status = 0;
123 	tty.ty_window = NULL;
124 	tty.ty_group  = _TTYS_NOGROUP;
125 
126 	for (; *p; p = skip(p)) {
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_INSECURE))
134 			tty.ty_status &= ~TTY_SECURE;
135 		else if (scmp(_TTYS_DIALUP))
136 			tty.ty_status |= TTY_DIALUP;
137 		else if (scmp(_TTYS_NETWORK))
138 			tty.ty_status |= TTY_NETWORK;
139 		else if (vcmp(_TTYS_WINDOW))
140 			tty.ty_window = value(p);
141 		else if (vcmp(_TTYS_GROUP))
142 			tty.ty_group = value(p);
143 		else
144 			break;
145 	}
146 
147 	if (zapchar == '#' || *p == '#')
148 		while ((c = *++p) == ' ' || c == '\t')
149 			;
150 	tty.ty_comment = p;
151 	if (*p == 0)
152 		tty.ty_comment = 0;
153 	if ( (p = index(p, '\n')) )
154 		*p = '\0';
155 	return (&tty);
156 }
157 
158 #define	QUOTED	1
159 
160 /*
161  * Skip over the current field, removing quotes, and return a pointer to
162  * the next field.
163  */
164 static char *
165 skip(p)
166 	register char *p;
167 {
168 	register char *t;
169 	register int c, q;
170 
171 	for (q = 0, t = p; (c = *p) != '\0'; p++) {
172 		if (c == '"') {
173 			q ^= QUOTED;	/* obscure, but nice */
174 			continue;
175 		}
176 		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
177 			p++;
178 		*t++ = *p;
179 		if (q == QUOTED)
180 			continue;
181 		if (c == '#') {
182 			zapchar = c;
183 			*p = 0;
184 			break;
185 		}
186 		if (c == '\t' || c == ' ' || c == '\n') {
187 			zapchar = c;
188 			*p++ = 0;
189 			while ((c = *p) == '\t' || c == ' ' || c == '\n')
190 				p++;
191 			break;
192 		}
193 	}
194 	*--t = '\0';
195 	return (p);
196 }
197 
198 static char *
199 value(p)
200 	register char *p;
201 {
202 
203 	return ((p = index(p, '=')) ? ++p : NULL);
204 }
205 
206 int
207 setttyent()
208 {
209 
210 	if (line == NULL) {
211 		if ((line = malloc(MALLOCCHUNK)) == NULL)
212 			return (0);
213 		lbsize = MALLOCCHUNK;
214 	}
215 	if (tf) {
216 		rewind(tf);
217 		return (1);
218 	} else if ( (tf = fopen(_PATH_TTYS, "r")) )
219 		return (1);
220 	return (0);
221 }
222 
223 int
224 endttyent()
225 {
226 	int rval;
227 
228 	/*
229          * NB: Don't free `line' because getttynam()
230 	 * may still be referencing it
231 	 */
232 	if (tf) {
233 		rval = (fclose(tf) != EOF);
234 		tf = NULL;
235 		return (rval);
236 	}
237 	return (1);
238 }
239 
240 static int
241 isttystat(tty, flag)
242 	const char *tty;
243 	int flag;
244 {
245 	register struct ttyent *t;
246 
247 	return ((t = getttynam(tty)) == NULL) ? 0 : !!(t->ty_status & flag);
248 }
249 
250 
251 int
252 isdialuptty(tty)
253 	const char *tty;
254 {
255 
256 	return isttystat(tty, TTY_DIALUP);
257 }
258 
259 int isnettty(tty)
260 	const char *tty;
261 {
262 
263 	return isttystat(tty, TTY_NETWORK);
264 }
265