xref: /freebsd/bin/kenv/kenv.c (revision 2b15cb3d0922bd70ea592f0da9b4a5b167f4d53f)
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 
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28 
29 #include <sys/types.h>
30 #include <sys/sysctl.h>
31 #include <err.h>
32 #include <kenv.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <unistd.h>
37 
38 static void	usage(void);
39 static int	kdumpenv(void);
40 static int	kgetenv(const char *);
41 static int	ksetenv(const char *, char *);
42 static int	kunsetenv(const char *);
43 
44 static int hflag = 0;
45 static int Nflag = 0;
46 static int qflag = 0;
47 static int uflag = 0;
48 static int vflag = 0;
49 
50 static void
51 usage(void)
52 {
53 	(void)fprintf(stderr, "%s\n%s\n%s\n",
54 	    "usage: kenv [-hNq]",
55 	    "       kenv [-qv] variable[=value]",
56 	    "       kenv [-q] -u variable");
57 	exit(1);
58 }
59 
60 int
61 main(int argc, char **argv)
62 {
63 	char *env, *eq, *val;
64 	int ch, error;
65 
66 	error = 0;
67 	val = NULL;
68 	env = NULL;
69 	while ((ch = getopt(argc, argv, "hNquv")) != -1) {
70 		switch (ch) {
71 		case 'h':
72 			hflag++;
73 			break;
74 		case 'N':
75 			Nflag++;
76 			break;
77 		case 'q':
78 			qflag++;
79 			break;
80 		case 'u':
81 			uflag++;
82 			break;
83 		case 'v':
84 			vflag++;
85 			break;
86 		default:
87 			usage();
88 		}
89 	}
90 	argc -= optind;
91 	argv += optind;
92 	if (argc > 0) {
93 		env = argv[0];
94 		eq = strchr(env, '=');
95 		if (eq != NULL) {
96 			*eq++ = '\0';
97 			val = eq;
98 		}
99 		argv++;
100 		argc--;
101 	}
102 	if ((hflag || Nflag) && env != NULL)
103 		usage();
104 	if (argc > 0 || ((uflag || vflag) && env == NULL))
105 		usage();
106 	if (env == NULL) {
107 		error = kdumpenv();
108 		if (error && !qflag)
109 			warn("kdumpenv");
110 	} else if (val == NULL) {
111 		if (uflag) {
112 			error = kunsetenv(env);
113 			if (error && !qflag)
114 				warnx("unable to unset %s", env);
115 		} else {
116 			error = kgetenv(env);
117 			if (error && !qflag)
118 				warnx("unable to get %s", env);
119 		}
120 	} else {
121 		error = ksetenv(env, val);
122 		if (error && !qflag)
123 			warnx("unable to set %s to %s", env, val);
124 	}
125 	return (error);
126 }
127 
128 static int
129 kdumpenv(void)
130 {
131 	char *buf, *cp;
132 	int buflen, envlen;
133 
134 	envlen = kenv(KENV_DUMP, NULL, NULL, 0);
135 	if (envlen < 0)
136 		return (-1);
137 	for (;;) {
138 		buflen = envlen * 120 / 100;
139 		buf = malloc(buflen + 1);
140 		if (buf == NULL)
141 			return (-1);
142 		memset(buf, 0, buflen + 1);	/* Be defensive */
143 		envlen = kenv(KENV_DUMP, NULL, buf, buflen);
144 		if (envlen < 0) {
145 			free(buf);
146 			return (-1);
147 		}
148 		if (envlen > buflen)
149 			free(buf);
150 		else
151 			break;
152 	}
153 
154 	for (; *buf != '\0'; buf += strlen(buf) + 1) {
155 		if (hflag) {
156 			if (strncmp(buf, "hint.", 5) != 0)
157 				continue;
158 		}
159 		cp = strchr(buf, '=');
160 		if (cp == NULL)
161 			continue;
162 		*cp++ = '\0';
163 		if (Nflag)
164 			printf("%s\n", buf);
165 		else
166 			printf("%s=\"%s\"\n", buf, cp);
167 		buf = cp;
168 	}
169 	return (0);
170 }
171 
172 static int
173 kgetenv(const char *env)
174 {
175 	char buf[1024];
176 	int ret;
177 
178 	ret = kenv(KENV_GET, env, buf, sizeof(buf));
179 	if (ret == -1)
180 		return (ret);
181 	if (vflag)
182 		printf("%s=\"%s\"\n", env, buf);
183 	else
184 		printf("%s\n", buf);
185 	return (0);
186 }
187 
188 static int
189 ksetenv(const char *env, char *val)
190 {
191 	int ret;
192 
193 	ret = kenv(KENV_SET, env, val, strlen(val)+1);
194 	if (ret == 0)
195 		printf("%s=\"%s\"\n", env, val);
196 	return (ret);
197 }
198 
199 static int
200 kunsetenv(const char *env)
201 {
202 	int ret;
203 
204 	ret = kenv(KENV_UNSET, env, NULL, 0);
205 	return (ret);
206 }
207