xref: /openbsd/lib/libc/gen/getttyent.c (revision cca36db2)
1 /*	$OpenBSD: getttyent.c,v 1.12 2009/11/09 00:18:27 kurt Exp $ */
2 /*
3  * Copyright (c) 1989, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <ttyent.h>
32 #include <stdio.h>
33 #include <ctype.h>
34 #include <string.h>
35 
36 static char zapchar;
37 static FILE *tf;
38 
39 static char *skip(char *);
40 static char *value(char *);
41 
42 struct ttyent *
43 getttynam(const char *tty)
44 {
45 	struct ttyent *t;
46 
47 	setttyent();
48 	while ((t = getttyent()))
49 		if (!strcmp(tty, t->ty_name))
50 			break;
51 	endttyent();
52 	return (t);
53 }
54 
55 struct ttyent *
56 getttyent(void)
57 {
58 	static struct ttyent tty;
59 	int c;
60 	char *p;
61 #define	MAXLINELENGTH	200
62 	static char line[MAXLINELENGTH];
63 
64 	if (!tf && !setttyent())
65 		return (NULL);
66 	for (;;) {
67 		if (!fgets(p = line, sizeof(line), tf))
68 			return (NULL);
69 		/* skip lines that are too big */
70 		if (!strchr(p, '\n')) {
71 			while ((c = getc_unlocked(tf)) != '\n' && c != EOF)
72 				;
73 			continue;
74 		}
75 		while (isspace(*p))
76 			++p;
77 		if (*p && *p != '#')
78 			break;
79 	}
80 
81 	zapchar = 0;
82 	tty.ty_name = p;
83 	p = skip(p);
84 	if (!*(tty.ty_getty = p))
85 		tty.ty_getty = tty.ty_type = NULL;
86 	else {
87 		p = skip(p);
88 		if (!*(tty.ty_type = p))
89 			tty.ty_type = NULL;
90 		else
91 			p = skip(p);
92 	}
93 	tty.ty_status = 0;
94 	tty.ty_window = NULL;
95 
96 #define	scmp(e)	!strncmp(p, e, sizeof(e) - 1) && isspace(p[sizeof(e) - 1])
97 #define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
98 	for (; *p; p = skip(p)) {
99 		if (scmp(_TTYS_OFF))
100 			tty.ty_status &= ~TTY_ON;
101 		else if (scmp(_TTYS_ON))
102 			tty.ty_status |= TTY_ON;
103 		else if (scmp(_TTYS_SECURE))
104 			tty.ty_status |= TTY_SECURE;
105 		else if (scmp(_TTYS_LOCAL))
106 			tty.ty_status |= TTY_LOCAL;
107 		else if (scmp(_TTYS_RTSCTS))
108 			tty.ty_status |= TTY_RTSCTS;
109 		else if (scmp(_TTYS_SOFTCAR))
110 			tty.ty_status |= TTY_SOFTCAR;
111 		else if (scmp(_TTYS_MDMBUF))
112 			tty.ty_status |= TTY_MDMBUF;
113 		else if (vcmp(_TTYS_WINDOW))
114 			tty.ty_window = value(p);
115 		else
116 			break;
117 	}
118 
119 	if (zapchar == '#' || *p == '#')
120 		while ((c = *++p) == ' ' || c == '\t')
121 			;
122 	tty.ty_comment = p;
123 	if (*p == 0)
124 		tty.ty_comment = 0;
125 	if ((p = strchr(p, '\n')))
126 		*p = '\0';
127 	return (&tty);
128 }
129 
130 #define	QUOTED	1
131 
132 /*
133  * Skip over the current field, removing quotes, and return a pointer to
134  * the next field.
135  */
136 static char *
137 skip(char *p)
138 {
139 	char *t;
140 	int c, q;
141 
142 	for (q = 0, t = p; (c = *p) != '\0'; p++) {
143 		if (c == '"') {
144 			q ^= QUOTED;	/* obscure, but nice */
145 			continue;
146 		}
147 		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
148 			p++;
149 		*t++ = *p;
150 		if (q == QUOTED)
151 			continue;
152 		if (c == '#') {
153 			zapchar = c;
154 			*p = 0;
155 			break;
156 		}
157 		if (c == '\t' || c == ' ' || c == '\n') {
158 			zapchar = c;
159 			*p++ = 0;
160 			while ((c = *p) == '\t' || c == ' ' || c == '\n')
161 				p++;
162 			break;
163 		}
164 	}
165 	*--t = '\0';
166 	return (p);
167 }
168 
169 static char *
170 value(char *p)
171 {
172 
173 	return ((p = strchr(p, '=')) ? ++p : NULL);
174 }
175 
176 int
177 setttyent(void)
178 {
179 
180 	if (tf) {
181 		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(void)
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