xref: /src/bin/kenv/kenv.c (revision 5705d171dacc69bcdbfc17849a9dc898249dae2e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2000  Peter Wemm <peter@freebsd.org>
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  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/types.h>
29 #include <sys/sysctl.h>
30 #include <err.h>
31 #include <errno.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(int dump_type);
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 lflag = 0;
46 static int Nflag = 0;
47 static int qflag = 0;
48 static int sflag = 0;
49 static int uflag = 0;
50 static int vflag = 0;
51 
52 static void
usage(void)53 usage(void)
54 {
55 	(void)fprintf(stderr, "%s\n%s\n%s\n",
56 	    "usage: kenv [-l|-s] [-hNq]",
57 	    "       kenv [-qv] variable[=value]",
58 	    "       kenv [-q] -u variable");
59 	exit(1);
60 }
61 
62 int
main(int argc,char ** argv)63 main(int argc, char **argv)
64 {
65 	char *env, *eq, *val;
66 	int ch, error;
67 
68 	val = NULL;
69 	env = NULL;
70 	while ((ch = getopt(argc, argv, "hlNqsuv")) != -1) {
71 		switch (ch) {
72 		case 'h':
73 			hflag++;
74 			break;
75 		case 'l':
76 			lflag++;
77 			break;
78 		case 'N':
79 			Nflag++;
80 			break;
81 		case 'q':
82 			qflag++;
83 			break;
84 		case 's':
85 			sflag++;
86 			break;
87 		case 'u':
88 			uflag++;
89 			break;
90 		case 'v':
91 			vflag++;
92 			break;
93 		default:
94 			usage();
95 		}
96 	}
97 	argc -= optind;
98 	argv += optind;
99 	if (argc > 0) {
100 		env = argv[0];
101 		eq = strchr(env, '=');
102 		if (eq != NULL) {
103 			*eq++ = '\0';
104 			val = eq;
105 		}
106 		argv++;
107 		argc--;
108 	}
109 	if ((hflag || Nflag) && env != NULL)
110 		usage();
111 	if (lflag && sflag)
112 		usage();
113 	if (argc > 0 || ((uflag || vflag) && env == NULL))
114 		usage();
115 	if (env == NULL) {
116 		if (lflag)
117 			error = kdumpenv(KENV_DUMP_LOADER);
118 		else if (sflag)
119 			error = kdumpenv(KENV_DUMP_STATIC);
120 		else
121 			error = kdumpenv(KENV_DUMP);
122 		if (error && !qflag) {
123 			if (errno == ENOENT)
124 				warnx("requested environment is unavailable");
125 			else
126 				warn("kdumpenv");
127 		}
128 	} else if (val == NULL) {
129 		if (uflag) {
130 			error = kunsetenv(env);
131 			if (error && !qflag)
132 				warnx("unable to unset %s", env);
133 		} else {
134 			error = kgetenv(env);
135 			if (error && !qflag)
136 				warnx("unable to get %s", env);
137 		}
138 	} else {
139 		error = ksetenv(env, val);
140 		if (error && !qflag)
141 			warnx("unable to set %s to %s", env, val);
142 	}
143 	return (error);
144 }
145 
146 static int
kdumpenv(int dump_type)147 kdumpenv(int dump_type)
148 {
149 	char *buf, *bp, *cp;
150 	int buflen, envlen;
151 
152 	envlen = kenv(dump_type, NULL, NULL, 0);
153 	if (envlen < 0)
154 		return (-1);
155 	for (;;) {
156 		buflen = envlen * 120 / 100;
157 		buf = calloc(1, buflen + 1);
158 		if (buf == NULL)
159 			return (-1);
160 		envlen = kenv(dump_type, NULL, buf, buflen);
161 		if (envlen < 0) {
162 			free(buf);
163 			return (-1);
164 		}
165 		if (envlen > buflen)
166 			free(buf);
167 		else
168 			break;
169 	}
170 
171 	for (bp = buf; *bp != '\0'; bp += strlen(bp) + 1) {
172 		if (hflag) {
173 			if (strncmp(bp, "hint.", 5) != 0)
174 				continue;
175 		}
176 		cp = strchr(bp, '=');
177 		if (cp == NULL)
178 			continue;
179 		*cp++ = '\0';
180 		if (Nflag)
181 			printf("%s\n", bp);
182 		else
183 			printf("%s=\"%s\"\n", bp, cp);
184 		bp = cp;
185 	}
186 
187 	free(buf);
188 	return (0);
189 }
190 
191 static int
kgetenv(const char * env)192 kgetenv(const char *env)
193 {
194 	char buf[1024];
195 	int ret;
196 
197 	ret = kenv(KENV_GET, env, buf, sizeof(buf));
198 	if (ret == -1)
199 		return (ret);
200 	if (vflag)
201 		printf("%s=\"%s\"\n", env, buf);
202 	else
203 		printf("%s\n", buf);
204 	return (0);
205 }
206 
207 static int
ksetenv(const char * env,char * val)208 ksetenv(const char *env, char *val)
209 {
210 	int ret;
211 
212 	ret = kenv(KENV_SET, env, val, strlen(val) + 1);
213 	if (ret == 0)
214 		printf("%s=\"%s\"\n", env, val);
215 	return (ret);
216 }
217 
218 static int
kunsetenv(const char * env)219 kunsetenv(const char *env)
220 {
221 	int ret;
222 
223 	ret = kenv(KENV_UNSET, env, NULL, 0);
224 	return (ret);
225 }
226