1 /* vi: set sw=4 ts=4: */
2 /*
3  * env implementation for busybox
4  *
5  * Copyright (c) 1988, 1993, 1994
6  * The Regents of the University of California.  All rights reserved.
7  *
8  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
9  *
10  * Original copyright notice is retained at the end of this file.
11  *
12  * Modified for BusyBox by Erik Andersen <andersen@codepoet.org>
13  */
14 /* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
15  *
16  * Fixed bug involving exit return codes if execvp fails.  Also added
17  * output error checking.
18  */
19 /*
20  * Modified by Vladimir Oleynik <dzo@simtreas.ru> (C) 2003
21  * - correct "-" option usage
22  * - multiple "-u unsetenv" support
23  * - GNU long option support
24  * - use xfunc_error_retval
25  */
26 //config:config ENV
27 //config:	bool "env (4 kb)"
28 //config:	default y
29 //config:	help
30 //config:	env is used to set an environment variable and run
31 //config:	a command; without options it displays the current
32 //config:	environment.
33 
34 //applet:IF_ENV(APPLET_NOEXEC(env, env, BB_DIR_USR_BIN, BB_SUID_DROP, env))
35 
36 //kbuild:lib-$(CONFIG_ENV) += env.o
37 
38 /* BB_AUDIT SUSv3 compliant */
39 /* http://www.opengroup.org/onlinepubs/007904975/utilities/env.html */
40 
41 //usage:#define env_trivial_usage
42 //usage:       "[-i0] [-u NAME]... [-] [NAME=VALUE]... [PROG ARGS]"
43 // The "-" can occur only once (unlike, say, -i): it terminates option processing,
44 // so if it is followed by another "-" arg (or any option-looking arg),
45 // that arg will be taken as PROG (or even as NAME=VALUE, example: "-z=QWE").
46 //usage:#define env_full_usage "\n\n"
47 //usage:       "Print current environment or run PROG after setting up environment\n"
48 //usage:     "\n	-, -i	Start with empty environment"
49 //usage:     "\n	-0	NUL terminated output"
50 //usage:     "\n	-u NAME	Remove variable from environment"
51 
52 #include "libbb.h"
53 
54 int env_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
env_main(int argc UNUSED_PARAM,char ** argv)55 int env_main(int argc UNUSED_PARAM, char **argv)
56 {
57 	unsigned opts;
58 	llist_t *unset_env = NULL;
59 
60 	opts = getopt32long(argv, "+i0u:*",
61 			"ignore-environment\0" No_argument       "i"
62 			"null\0"               No_argument       "0"
63 			"unset\0"              Required_argument "u"
64 			, &unset_env
65 	);
66 	argv += optind;
67 	if (argv[0] && LONE_DASH(argv[0])) {
68 		opts |= 1;
69 		++argv;
70 	}
71 	if (opts & 1) {
72 		clearenv();
73 	}
74 	while (unset_env) {
75 		char *var = llist_pop(&unset_env);
76 		/* This does not handle -uVAR=VAL
77 		 * (coreutils _sets_ the variable in that case): */
78 		/*unsetenv(var);*/
79 		/* This does, but uses somewhan undocumented feature that
80 		 * putenv("name_without_equal_sign") unsets the variable: */
81 		putenv(var);
82 	}
83 
84 	while (*argv && (strchr(*argv, '=') != NULL)) {
85 		if (putenv(*argv) < 0) {
86 			bb_simple_perror_msg_and_die("putenv");
87 		}
88 		++argv;
89 	}
90 
91 	if (argv[0]) {
92 		BB_EXECVP_or_die(argv);
93 	}
94 
95 	if (environ) { /* clearenv() may set environ == NULL! */
96 		char **ep;
97 		opts = (opts & 2) ? 0 : '\n';
98 		for (ep = environ; *ep; ep++) {
99 			printf("%s%c", *ep, opts);
100 		}
101 	}
102 
103 	fflush_stdout_and_exit(EXIT_SUCCESS);
104 }
105 
106 /*
107  * Copyright (c) 1988, 1993, 1994
108  *      The Regents of the University of California.  All rights reserved.
109  *
110  * Redistribution and use in source and binary forms, with or without
111  * modification, are permitted provided that the following conditions
112  * are met:
113  * 1. Redistributions of source code must retain the above copyright
114  *    notice, this list of conditions and the following disclaimer.
115  * 2. Redistributions in binary form must reproduce the above copyright
116  *    notice, this list of conditions and the following disclaimer in the
117  *    documentation and/or other materials provided with the distribution.
118  *
119  * 3. BSD Advertising Clause omitted per the July 22, 1999 licensing change
120  *    ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
121  *
122  * 4. Neither the name of the University nor the names of its contributors
123  *    may be used to endorse or promote products derived from this software
124  *    without specific prior written permission.
125  *
126  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND
127  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
128  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
129  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
130  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
131  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
132  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
133  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
134  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
135  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
136  * SUCH DAMAGE.
137  */
138