xref: /freebsd/bin/kenv/kenv.c (revision 2e3f49888ec8851bafb22011533217487764fdb0)
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/types.h>
27 #include <sys/sysctl.h>
28 #include <err.h>
29 #include <errno.h>
30 #include <kenv.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <unistd.h>
35 
36 static void	usage(void);
37 static int	kdumpenv(int dump_type);
38 static int	kgetenv(const char *);
39 static int	ksetenv(const char *, char *);
40 static int	kunsetenv(const char *);
41 
42 static int hflag = 0;
43 static int lflag = 0;
44 static int Nflag = 0;
45 static int qflag = 0;
46 static int sflag = 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 [-l|-s] [-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 	val = NULL;
67 	env = NULL;
68 	while ((ch = getopt(argc, argv, "hlNqsuv")) != -1) {
69 		switch (ch) {
70 		case 'h':
71 			hflag++;
72 			break;
73 		case 'l':
74 			lflag++;
75 			break;
76 		case 'N':
77 			Nflag++;
78 			break;
79 		case 'q':
80 			qflag++;
81 			break;
82 		case 's':
83 			sflag++;
84 			break;
85 		case 'u':
86 			uflag++;
87 			break;
88 		case 'v':
89 			vflag++;
90 			break;
91 		default:
92 			usage();
93 		}
94 	}
95 	argc -= optind;
96 	argv += optind;
97 	if (argc > 0) {
98 		env = argv[0];
99 		eq = strchr(env, '=');
100 		if (eq != NULL) {
101 			*eq++ = '\0';
102 			val = eq;
103 		}
104 		argv++;
105 		argc--;
106 	}
107 	if ((hflag || Nflag) && env != NULL)
108 		usage();
109 	if (lflag && sflag)
110 		usage();
111 	if (argc > 0 || ((uflag || vflag) && env == NULL))
112 		usage();
113 	if (env == NULL) {
114 		if (lflag)
115 			error = kdumpenv(KENV_DUMP_LOADER);
116 		else if (sflag)
117 			error = kdumpenv(KENV_DUMP_STATIC);
118 		else
119 			error = kdumpenv(KENV_DUMP);
120 		if (error && !qflag) {
121 			if (errno == ENOENT)
122 				warnx("requested environment is unavailable");
123 			else
124 				warn("kdumpenv");
125 		}
126 	} else if (val == NULL) {
127 		if (uflag) {
128 			error = kunsetenv(env);
129 			if (error && !qflag)
130 				warnx("unable to unset %s", env);
131 		} else {
132 			error = kgetenv(env);
133 			if (error && !qflag)
134 				warnx("unable to get %s", env);
135 		}
136 	} else {
137 		error = ksetenv(env, val);
138 		if (error && !qflag)
139 			warnx("unable to set %s to %s", env, val);
140 	}
141 	return (error);
142 }
143 
144 static int
145 kdumpenv(int dump_type)
146 {
147 	char *buf, *bp, *cp;
148 	int buflen, envlen;
149 
150 	envlen = kenv(dump_type, NULL, NULL, 0);
151 	if (envlen < 0)
152 		return (-1);
153 	for (;;) {
154 		buflen = envlen * 120 / 100;
155 		buf = calloc(1, buflen + 1);
156 		if (buf == NULL)
157 			return (-1);
158 		envlen = kenv(dump_type, NULL, buf, buflen);
159 		if (envlen < 0) {
160 			free(buf);
161 			return (-1);
162 		}
163 		if (envlen > buflen)
164 			free(buf);
165 		else
166 			break;
167 	}
168 
169 	for (bp = buf; *bp != '\0'; bp += strlen(bp) + 1) {
170 		if (hflag) {
171 			if (strncmp(bp, "hint.", 5) != 0)
172 				continue;
173 		}
174 		cp = strchr(bp, '=');
175 		if (cp == NULL)
176 			continue;
177 		*cp++ = '\0';
178 		if (Nflag)
179 			printf("%s\n", bp);
180 		else
181 			printf("%s=\"%s\"\n", bp, cp);
182 		bp = cp;
183 	}
184 
185 	free(buf);
186 	return (0);
187 }
188 
189 static int
190 kgetenv(const char *env)
191 {
192 	char buf[1024];
193 	int ret;
194 
195 	ret = kenv(KENV_GET, env, buf, sizeof(buf));
196 	if (ret == -1)
197 		return (ret);
198 	if (vflag)
199 		printf("%s=\"%s\"\n", env, buf);
200 	else
201 		printf("%s\n", buf);
202 	return (0);
203 }
204 
205 static int
206 ksetenv(const char *env, char *val)
207 {
208 	int ret;
209 
210 	ret = kenv(KENV_SET, env, val, strlen(val) + 1);
211 	if (ret == 0)
212 		printf("%s=\"%s\"\n", env, val);
213 	return (ret);
214 }
215 
216 static int
217 kunsetenv(const char *env)
218 {
219 	int ret;
220 
221 	ret = kenv(KENV_UNSET, env, NULL, 0);
222 	return (ret);
223 }
224