xref: /freebsd/bin/kenv/kenv.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
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 #include <sys/types.h>
28 #include <sys/sysctl.h>
29 #include <err.h>
30 #include <errno.h>
31 #include <kenv.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <unistd.h>
36 
37 static void	usage(void);
38 static int	kdumpenv(int dump_type);
39 static int	kgetenv(const char *);
40 static int	ksetenv(const char *, char *);
41 static int	kunsetenv(const char *);
42 
43 static int hflag = 0;
44 static int lflag = 0;
45 static int Nflag = 0;
46 static int qflag = 0;
47 static int sflag = 0;
48 static int uflag = 0;
49 static int vflag = 0;
50 
51 static void
52 usage(void)
53 {
54 	(void)fprintf(stderr, "%s\n%s\n%s\n",
55 	    "usage: kenv [-l|-s] [-hNq]",
56 	    "       kenv [-qv] variable[=value]",
57 	    "       kenv [-q] -u variable");
58 	exit(1);
59 }
60 
61 int
62 main(int argc, char **argv)
63 {
64 	char *env, *eq, *val;
65 	int ch, error;
66 
67 	val = NULL;
68 	env = NULL;
69 	while ((ch = getopt(argc, argv, "hlNqsuv")) != -1) {
70 		switch (ch) {
71 		case 'h':
72 			hflag++;
73 			break;
74 		case 'l':
75 			lflag++;
76 			break;
77 		case 'N':
78 			Nflag++;
79 			break;
80 		case 'q':
81 			qflag++;
82 			break;
83 		case 's':
84 			sflag++;
85 			break;
86 		case 'u':
87 			uflag++;
88 			break;
89 		case 'v':
90 			vflag++;
91 			break;
92 		default:
93 			usage();
94 		}
95 	}
96 	argc -= optind;
97 	argv += optind;
98 	if (argc > 0) {
99 		env = argv[0];
100 		eq = strchr(env, '=');
101 		if (eq != NULL) {
102 			*eq++ = '\0';
103 			val = eq;
104 		}
105 		argv++;
106 		argc--;
107 	}
108 	if ((hflag || Nflag) && env != NULL)
109 		usage();
110 	if (lflag && sflag)
111 		usage();
112 	if (argc > 0 || ((uflag || vflag) && env == NULL))
113 		usage();
114 	if (env == NULL) {
115 		if (lflag)
116 			error = kdumpenv(KENV_DUMP_LOADER);
117 		else if (sflag)
118 			error = kdumpenv(KENV_DUMP_STATIC);
119 		else
120 			error = kdumpenv(KENV_DUMP);
121 		if (error && !qflag) {
122 			if (errno == ENOENT)
123 				warnx("requested environment is unavailable");
124 			else
125 				warn("kdumpenv");
126 		}
127 	} else if (val == NULL) {
128 		if (uflag) {
129 			error = kunsetenv(env);
130 			if (error && !qflag)
131 				warnx("unable to unset %s", env);
132 		} else {
133 			error = kgetenv(env);
134 			if (error && !qflag)
135 				warnx("unable to get %s", env);
136 		}
137 	} else {
138 		error = ksetenv(env, val);
139 		if (error && !qflag)
140 			warnx("unable to set %s to %s", env, val);
141 	}
142 	return (error);
143 }
144 
145 static int
146 kdumpenv(int dump_type)
147 {
148 	char *buf, *bp, *cp;
149 	int buflen, envlen;
150 
151 	envlen = kenv(dump_type, NULL, NULL, 0);
152 	if (envlen < 0)
153 		return (-1);
154 	for (;;) {
155 		buflen = envlen * 120 / 100;
156 		buf = calloc(1, buflen + 1);
157 		if (buf == NULL)
158 			return (-1);
159 		envlen = kenv(dump_type, NULL, buf, buflen);
160 		if (envlen < 0) {
161 			free(buf);
162 			return (-1);
163 		}
164 		if (envlen > buflen)
165 			free(buf);
166 		else
167 			break;
168 	}
169 
170 	for (bp = buf; *bp != '\0'; bp += strlen(bp) + 1) {
171 		if (hflag) {
172 			if (strncmp(bp, "hint.", 5) != 0)
173 				continue;
174 		}
175 		cp = strchr(bp, '=');
176 		if (cp == NULL)
177 			continue;
178 		*cp++ = '\0';
179 		if (Nflag)
180 			printf("%s\n", bp);
181 		else
182 			printf("%s=\"%s\"\n", bp, cp);
183 		bp = cp;
184 	}
185 
186 	free(buf);
187 	return (0);
188 }
189 
190 static int
191 kgetenv(const char *env)
192 {
193 	char buf[1024];
194 	int ret;
195 
196 	ret = kenv(KENV_GET, env, buf, sizeof(buf));
197 	if (ret == -1)
198 		return (ret);
199 	if (vflag)
200 		printf("%s=\"%s\"\n", env, buf);
201 	else
202 		printf("%s\n", buf);
203 	return (0);
204 }
205 
206 static int
207 ksetenv(const char *env, char *val)
208 {
209 	int ret;
210 
211 	ret = kenv(KENV_SET, env, val, strlen(val) + 1);
212 	if (ret == 0)
213 		printf("%s=\"%s\"\n", env, val);
214 	return (ret);
215 }
216 
217 static int
218 kunsetenv(const char *env)
219 {
220 	int ret;
221 
222 	ret = kenv(KENV_UNSET, env, NULL, 0);
223 	return (ret);
224 }
225