xref: /freebsd/lib/libc/gen/getttyent.c (revision afe61c15161c324a7af299a9b8457aba5afc92db)
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 <ctype.h>
41 #include <string.h>
42 
43 static char zapchar;
44 static FILE *tf;
45 
46 struct ttyent *
47 getttynam(tty)
48 	const char *tty;
49 {
50 	register struct ttyent *t;
51 
52 	setttyent();
53 	while (t = getttyent())
54 		if (!strcmp(tty, t->ty_name))
55 			break;
56 	endttyent();
57 	return (t);
58 }
59 
60 struct ttyent *
61 getttyent()
62 {
63 	static struct ttyent tty;
64 	register int c;
65 	register char *p;
66 #define	MAXLINELENGTH	100
67 	static char line[MAXLINELENGTH];
68 	static char *skip(), *value();
69 
70 	if (!tf && !setttyent())
71 		return (NULL);
72 	for (;;) {
73 		if (!fgets(p = line, sizeof(line), tf))
74 			return (NULL);
75 		/* skip lines that are too big */
76 		if (!index(p, '\n')) {
77 			while ((c = getc(tf)) != '\n' && c != EOF)
78 				;
79 			continue;
80 		}
81 		while (isspace(*p))
82 			++p;
83 		if (*p && *p != '#')
84 			break;
85 	}
86 
87 	zapchar = 0;
88 	tty.ty_name = p;
89 	p = skip(p);
90 	if (!*(tty.ty_getty = p))
91 		tty.ty_getty = tty.ty_type = NULL;
92 	else {
93 		p = skip(p);
94 		if (!*(tty.ty_type = p))
95 			tty.ty_type = NULL;
96 		else
97 			p = skip(p);
98 	}
99 	tty.ty_status = 0;
100 	tty.ty_window = NULL;
101 
102 #define	scmp(e)	!strncmp(p, e, sizeof(e) - 1) && isspace(p[sizeof(e) - 1])
103 #define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
104 	for (; *p; p = skip(p)) {
105 		if (scmp(_TTYS_OFF))
106 			tty.ty_status &= ~TTY_ON;
107 		else if (scmp(_TTYS_ON))
108 			tty.ty_status |= TTY_ON;
109 		else if (scmp(_TTYS_SECURE))
110 			tty.ty_status |= TTY_SECURE;
111 		else if (vcmp(_TTYS_WINDOW))
112 			tty.ty_window = value(p);
113 		else
114 			break;
115 	}
116 
117 	if (zapchar == '#' || *p == '#')
118 		while ((c = *++p) == ' ' || c == '\t')
119 			;
120 	tty.ty_comment = p;
121 	if (*p == 0)
122 		tty.ty_comment = 0;
123 	if (p = index(p, '\n'))
124 		*p = '\0';
125 	return (&tty);
126 }
127 
128 #define	QUOTED	1
129 
130 /*
131  * Skip over the current field, removing quotes, and return a pointer to
132  * the next field.
133  */
134 static char *
135 skip(p)
136 	register char *p;
137 {
138 	register char *t;
139 	register int c, q;
140 
141 	for (q = 0, t = p; (c = *p) != '\0'; p++) {
142 		if (c == '"') {
143 			q ^= QUOTED;	/* obscure, but nice */
144 			continue;
145 		}
146 		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
147 			p++;
148 		*t++ = *p;
149 		if (q == QUOTED)
150 			continue;
151 		if (c == '#') {
152 			zapchar = c;
153 			*p = 0;
154 			break;
155 		}
156 		if (c == '\t' || c == ' ' || c == '\n') {
157 			zapchar = c;
158 			*p++ = 0;
159 			while ((c = *p) == '\t' || c == ' ' || c == '\n')
160 				p++;
161 			break;
162 		}
163 	}
164 	*--t = '\0';
165 	return (p);
166 }
167 
168 static char *
169 value(p)
170 	register char *p;
171 {
172 
173 	return ((p = index(p, '=')) ? ++p : NULL);
174 }
175 
176 int
177 setttyent()
178 {
179 
180 	if (tf) {
181 		(void)rewind(tf);
182 		return (1);
183 	} else if (tf = fopen(_PATH_TTYS, "r"))
184 		return (1);
185 	return (0);
186 }
187 
188 int
189 endttyent()
190 {
191 	int rval;
192 
193 	if (tf) {
194 		rval = !(fclose(tf) == EOF);
195 		tf = NULL;
196 		return (rval);
197 	}
198 	return (1);
199 }
200