xref: /freebsd/bin/kenv/kenv.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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 	val = NULL;
67 	env = NULL;
68 	while ((ch = getopt(argc, argv, "hNquv")) != -1) {
69 		switch (ch) {
70 		case 'h':
71 			hflag++;
72 			break;
73 		case 'N':
74 			Nflag++;
75 			break;
76 		case 'q':
77 			qflag++;
78 			break;
79 		case 'u':
80 			uflag++;
81 			break;
82 		case 'v':
83 			vflag++;
84 			break;
85 		default:
86 			usage();
87 		}
88 	}
89 	argc -= optind;
90 	argv += optind;
91 	if (argc > 0) {
92 		env = argv[0];
93 		eq = strchr(env, '=');
94 		if (eq != NULL) {
95 			*eq++ = '\0';
96 			val = eq;
97 		}
98 		argv++;
99 		argc--;
100 	}
101 	if ((hflag || Nflag) && env != NULL)
102 		usage();
103 	if (argc > 0 || ((uflag || vflag) && env == NULL))
104 		usage();
105 	if (env == NULL) {
106 		error = kdumpenv();
107 		if (error && !qflag)
108 			warn("kdumpenv");
109 	} else if (val == NULL) {
110 		if (uflag) {
111 			error = kunsetenv(env);
112 			if (error && !qflag)
113 				warnx("unable to unset %s", env);
114 		} else {
115 			error = kgetenv(env);
116 			if (error && !qflag)
117 				warnx("unable to get %s", env);
118 		}
119 	} else {
120 		error = ksetenv(env, val);
121 		if (error && !qflag)
122 			warnx("unable to set %s to %s", env, val);
123 	}
124 	return (error);
125 }
126 
127 static int
128 kdumpenv(void)
129 {
130 	char *buf, *bp, *cp;
131 	int buflen, envlen;
132 
133 	envlen = kenv(KENV_DUMP, NULL, NULL, 0);
134 	if (envlen < 0)
135 		return (-1);
136 	for (;;) {
137 		buflen = envlen * 120 / 100;
138 		buf = calloc(1, buflen + 1);
139 		if (buf == NULL)
140 			return (-1);
141 		envlen = kenv(KENV_DUMP, NULL, buf, buflen);
142 		if (envlen < 0) {
143 			free(buf);
144 			return (-1);
145 		}
146 		if (envlen > buflen)
147 			free(buf);
148 		else
149 			break;
150 	}
151 
152 	for (bp = buf; *bp != '\0'; bp += strlen(bp) + 1) {
153 		if (hflag) {
154 			if (strncmp(bp, "hint.", 5) != 0)
155 				continue;
156 		}
157 		cp = strchr(bp, '=');
158 		if (cp == NULL)
159 			continue;
160 		*cp++ = '\0';
161 		if (Nflag)
162 			printf("%s\n", bp);
163 		else
164 			printf("%s=\"%s\"\n", bp, cp);
165 		bp = cp;
166 	}
167 
168 	free(buf);
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