xref: /freebsd/bin/kenv/kenv.c (revision 3ff369fed2a08f32dda232c10470b949bef9489f)
1 /*
2  * Copyright (c) 2000  Peter Wemm <peter@freebsd.org>
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  * $FreeBSD$
26  */
27 #include <sys/types.h>
28 #include <sys/sysctl.h>
29 #include <stdlib.h>
30 #include <stdio.h>
31 #include <string.h>
32 #include <errno.h>
33 #include <err.h>
34 #include <kenv.h>
35 #include <unistd.h>
36 
37 static void	usage(void);
38 static int	kdumpenv(void);
39 static int	kgetenv(char *);
40 static int	ksetenv(char *, char *);
41 static int	kunsetenv(char *);
42 
43 static int hflag = 0;
44 static int uflag = 0;
45 
46 static void
47 usage(void)
48 {
49 	(void)fprintf(stderr, "%s\n%s\n%s\n",
50 	    "usage: kenv [-h]",
51 	    "       kenv variable[=value]",
52 	    "       kenv -u variable");
53 	exit(1);
54 }
55 
56 int
57 main(int argc, char **argv)
58 {
59 	char *env, *eq, *val;
60 	int ch, error;
61 
62 	error = 0;
63 	val = NULL;
64 	env = NULL;
65 	while ((ch = getopt(argc, argv, "hu")) != -1) {
66 		switch (ch) {
67 		case 'h':
68 			hflag++;
69 			break;
70 		case 'u':
71 			uflag++;
72 			break;
73 		default:
74 			usage();
75 		}
76 	}
77 	argc -= optind;
78 	argv += optind;
79 	if (argc > 0) {
80 		env = argv[0];
81 		eq = strchr(env, '=');
82 		if (eq != NULL) {
83 			*eq++ = '\0';
84 			val = eq;
85 		}
86 		argv++;
87 		argc--;
88 	}
89 	if (hflag && (env != NULL))
90 		usage();
91 	if ((argc > 0) || (uflag && (env == NULL)))
92 		usage();
93 	if (env == NULL)
94 		kdumpenv();
95 	else if (val == NULL) {
96 		if (uflag) {
97 			error = kunsetenv(env);
98 			if (error)
99 				warnx("unable to unset %s", env);
100 		} else {
101 			error = kgetenv(env);
102 			if (error)
103 				warnx("unable to get %s", env);
104 		}
105 	} else {
106 		error = ksetenv(env, val);
107 		if (error)
108 			warnx("unable to set %s to %s", env, val);
109 	}
110 	return (error);
111 }
112 
113 static int
114 kdumpenv()
115 {
116 	char *buf, *cp;
117 	int len;
118 
119 	len = kenv(KENV_DUMP, NULL, NULL, 0);
120 	len = len * 120 / 100;
121 	buf = malloc(len);
122 	if (buf == NULL)
123 		return (-1);
124 	/* Be defensive */
125 	memset(buf, 0, len);
126 	kenv(KENV_DUMP, NULL, buf, len);
127 	for (; *buf != '\0'; buf += strlen(buf) + 1) {
128 		if (hflag) {
129 			if (strncmp(buf, "hint.", 5) != 0)
130 				continue;
131 		}
132 		cp = strchr(buf, '=');
133 		if (cp == NULL)
134 			continue;
135 		*cp++ = '\0';
136 		printf("%s=\"%s\"\n", buf, cp);
137 		buf = cp;
138 	}
139 	return (0);
140 }
141 
142 static int
143 kgetenv(char *env)
144 {
145 	char buf[1024];
146 	int ret;
147 
148 	ret = kenv(KENV_GET, env, buf, sizeof(buf));
149 	if (ret == -1)
150 		return (ret);
151 	printf("%s\n", buf);
152 	return (0);
153 }
154 
155 static int
156 ksetenv(char *env, char *val)
157 {
158 	int ret;
159 
160 	ret = kenv(KENV_SET, env, val, strlen(val)+1);
161 	if (ret == 0)
162 		printf("%s=\"%s\"\n", env, val);
163 	return (ret);
164 }
165 
166 static int
167 kunsetenv(char *env)
168 {
169 	int ret;
170 
171 	ret = kenv(KENV_UNSET, env, NULL, 0);
172 	return (ret);
173 }
174