xref: /freebsd/bin/kenv/kenv.c (revision d9a42747950146bf03cda7f6e25d219253f8a57a)
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 <errno.h>
33 #include <kenv.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <unistd.h>
38 
39 static void	usage(void);
40 static int	kdumpenv(int dump_type);
41 static int	kgetenv(const char *);
42 static int	ksetenv(const char *, char *);
43 static int	kunsetenv(const char *);
44 
45 static int hflag = 0;
46 static int lflag = 0;
47 static int Nflag = 0;
48 static int qflag = 0;
49 static int sflag = 0;
50 static int uflag = 0;
51 static int vflag = 0;
52 
53 static void
54 usage(void)
55 {
56 	(void)fprintf(stderr, "%s\n%s\n%s\n",
57 	    "usage: kenv [-l|-s] [-hNq]",
58 	    "       kenv [-qv] variable[=value]",
59 	    "       kenv [-q] -u variable");
60 	exit(1);
61 }
62 
63 int
64 main(int argc, char **argv)
65 {
66 	char *env, *eq, *val;
67 	int ch, error;
68 
69 	val = NULL;
70 	env = NULL;
71 	while ((ch = getopt(argc, argv, "hlNqsuv")) != -1) {
72 		switch (ch) {
73 		case 'h':
74 			hflag++;
75 			break;
76 		case 'l':
77 			lflag++;
78 			break;
79 		case 'N':
80 			Nflag++;
81 			break;
82 		case 'q':
83 			qflag++;
84 			break;
85 		case 's':
86 			sflag++;
87 			break;
88 		case 'u':
89 			uflag++;
90 			break;
91 		case 'v':
92 			vflag++;
93 			break;
94 		default:
95 			usage();
96 		}
97 	}
98 	argc -= optind;
99 	argv += optind;
100 	if (argc > 0) {
101 		env = argv[0];
102 		eq = strchr(env, '=');
103 		if (eq != NULL) {
104 			*eq++ = '\0';
105 			val = eq;
106 		}
107 		argv++;
108 		argc--;
109 	}
110 	if ((hflag || Nflag) && env != NULL)
111 		usage();
112 	if (lflag && sflag)
113 		usage();
114 	if (argc > 0 || ((uflag || vflag) && env == NULL))
115 		usage();
116 	if (env == NULL) {
117 		if (lflag)
118 			error = kdumpenv(KENV_DUMP_LOADER);
119 		else if (sflag)
120 			error = kdumpenv(KENV_DUMP_STATIC);
121 		else
122 			error = kdumpenv(KENV_DUMP);
123 		if (error && !qflag) {
124 			if (errno == ENOENT)
125 				warnx("requested environment is unavailable");
126 			else
127 				warn("kdumpenv");
128 		}
129 	} else if (val == NULL) {
130 		if (uflag) {
131 			error = kunsetenv(env);
132 			if (error && !qflag)
133 				warnx("unable to unset %s", env);
134 		} else {
135 			error = kgetenv(env);
136 			if (error && !qflag)
137 				warnx("unable to get %s", env);
138 		}
139 	} else {
140 		error = ksetenv(env, val);
141 		if (error && !qflag)
142 			warnx("unable to set %s to %s", env, val);
143 	}
144 	return (error);
145 }
146 
147 static int
148 kdumpenv(int dump_type)
149 {
150 	char *buf, *bp, *cp;
151 	int buflen, envlen;
152 
153 	envlen = kenv(dump_type, NULL, NULL, 0);
154 	if (envlen < 0)
155 		return (-1);
156 	for (;;) {
157 		buflen = envlen * 120 / 100;
158 		buf = calloc(1, buflen + 1);
159 		if (buf == NULL)
160 			return (-1);
161 		envlen = kenv(dump_type, NULL, buf, buflen);
162 		if (envlen < 0) {
163 			free(buf);
164 			return (-1);
165 		}
166 		if (envlen > buflen)
167 			free(buf);
168 		else
169 			break;
170 	}
171 
172 	for (bp = buf; *bp != '\0'; bp += strlen(bp) + 1) {
173 		if (hflag) {
174 			if (strncmp(bp, "hint.", 5) != 0)
175 				continue;
176 		}
177 		cp = strchr(bp, '=');
178 		if (cp == NULL)
179 			continue;
180 		*cp++ = '\0';
181 		if (Nflag)
182 			printf("%s\n", bp);
183 		else
184 			printf("%s=\"%s\"\n", bp, cp);
185 		bp = cp;
186 	}
187 
188 	free(buf);
189 	return (0);
190 }
191 
192 static int
193 kgetenv(const char *env)
194 {
195 	char buf[1024];
196 	int ret;
197 
198 	ret = kenv(KENV_GET, env, buf, sizeof(buf));
199 	if (ret == -1)
200 		return (ret);
201 	if (vflag)
202 		printf("%s=\"%s\"\n", env, buf);
203 	else
204 		printf("%s\n", buf);
205 	return (0);
206 }
207 
208 static int
209 ksetenv(const char *env, char *val)
210 {
211 	int ret;
212 
213 	ret = kenv(KENV_SET, env, val, strlen(val) + 1);
214 	if (ret == 0)
215 		printf("%s=\"%s\"\n", env, val);
216 	return (ret);
217 }
218 
219 static int
220 kunsetenv(const char *env)
221 {
222 	int ret;
223 
224 	ret = kenv(KENV_UNSET, env, NULL, 0);
225 	return (ret);
226 }
227