xref: /openbsd-src/lib/libc/gen/getttyent.c (revision db3296cf5c1dd9058ceecc3a29fe4aaa0bd26000)
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)
31 static char rcsid[] = "$OpenBSD: getttyent.c,v 1.6 2003/06/02 20:18:34 millert 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 
39 static char zapchar;
40 static FILE *tf;
41 
42 static char *skip(char *);
43 static char *value(char *);
44 
45 struct ttyent *
46 getttynam(tty)
47 	const char *tty;
48 {
49 	register struct ttyent *t;
50 
51 	setttyent();
52 	while ((t = getttyent()))
53 		if (!strcmp(tty, t->ty_name))
54 			break;
55 	endttyent();
56 	return (t);
57 }
58 
59 struct ttyent *
60 getttyent()
61 {
62 	static struct ttyent tty;
63 	register int c;
64 	register char *p;
65 #define	MAXLINELENGTH	200
66 	static char line[MAXLINELENGTH];
67 
68 	if (!tf && !setttyent())
69 		return (NULL);
70 	for (;;) {
71 		if (!fgets(p = line, sizeof(line), tf))
72 			return (NULL);
73 		/* skip lines that are too big */
74 		if (!strchr(p, '\n')) {
75 			while ((c = getc(tf)) != '\n' && c != EOF)
76 				;
77 			continue;
78 		}
79 		while (isspace(*p))
80 			++p;
81 		if (*p && *p != '#')
82 			break;
83 	}
84 
85 	zapchar = 0;
86 	tty.ty_name = p;
87 	p = skip(p);
88 	if (!*(tty.ty_getty = p))
89 		tty.ty_getty = tty.ty_type = NULL;
90 	else {
91 		p = skip(p);
92 		if (!*(tty.ty_type = p))
93 			tty.ty_type = NULL;
94 		else
95 			p = skip(p);
96 	}
97 	tty.ty_status = 0;
98 	tty.ty_window = NULL;
99 
100 #define	scmp(e)	!strncmp(p, e, sizeof(e) - 1) && isspace(p[sizeof(e) - 1])
101 #define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
102 	for (; *p; p = skip(p)) {
103 		if (scmp(_TTYS_OFF))
104 			tty.ty_status &= ~TTY_ON;
105 		else if (scmp(_TTYS_ON))
106 			tty.ty_status |= TTY_ON;
107 		else if (scmp(_TTYS_SECURE))
108 			tty.ty_status |= TTY_SECURE;
109 		else if (scmp(_TTYS_LOCAL))
110 			tty.ty_status |= TTY_LOCAL;
111 		else if (scmp(_TTYS_RTSCTS))
112 			tty.ty_status |= TTY_RTSCTS;
113 		else if (scmp(_TTYS_SOFTCAR))
114 			tty.ty_status |= TTY_SOFTCAR;
115 		else if (scmp(_TTYS_MDMBUF))
116 			tty.ty_status |= TTY_MDMBUF;
117 		else if (vcmp(_TTYS_WINDOW))
118 			tty.ty_window = value(p);
119 		else
120 			break;
121 	}
122 
123 	if (zapchar == '#' || *p == '#')
124 		while ((c = *++p) == ' ' || c == '\t')
125 			;
126 	tty.ty_comment = p;
127 	if (*p == 0)
128 		tty.ty_comment = 0;
129 	if ((p = strchr(p, '\n')))
130 		*p = '\0';
131 	return (&tty);
132 }
133 
134 #define	QUOTED	1
135 
136 /*
137  * Skip over the current field, removing quotes, and return a pointer to
138  * the next field.
139  */
140 static char *
141 skip(p)
142 	register char *p;
143 {
144 	register char *t;
145 	register int c, q;
146 
147 	for (q = 0, t = p; (c = *p) != '\0'; p++) {
148 		if (c == '"') {
149 			q ^= QUOTED;	/* obscure, but nice */
150 			continue;
151 		}
152 		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
153 			p++;
154 		*t++ = *p;
155 		if (q == QUOTED)
156 			continue;
157 		if (c == '#') {
158 			zapchar = c;
159 			*p = 0;
160 			break;
161 		}
162 		if (c == '\t' || c == ' ' || c == '\n') {
163 			zapchar = c;
164 			*p++ = 0;
165 			while ((c = *p) == '\t' || c == ' ' || c == '\n')
166 				p++;
167 			break;
168 		}
169 	}
170 	*--t = '\0';
171 	return (p);
172 }
173 
174 static char *
175 value(p)
176 	register char *p;
177 {
178 
179 	return ((p = strchr(p, '=')) ? ++p : NULL);
180 }
181 
182 int
183 setttyent()
184 {
185 
186 	if (tf) {
187 		rewind(tf);
188 		return (1);
189 	} else if ((tf = fopen(_PATH_TTYS, "r")))
190 		return (1);
191 	return (0);
192 }
193 
194 int
195 endttyent()
196 {
197 	int rval;
198 
199 	if (tf) {
200 		rval = !(fclose(tf) == EOF);
201 		tf = NULL;
202 		return (rval);
203 	}
204 	return (1);
205 }
206