xref: /freebsd/usr.bin/env/env.c (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1988, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef lint
33 static const char copyright[] =
34 "@(#) Copyright (c) 1988, 1993, 1994\n\
35 	The Regents of the University of California.  All rights reserved.\n";
36 #endif /* not lint */
37 
38 #if 0
39 #ifndef lint
40 static char sccsid[] = "@(#)env.c	8.3 (Berkeley) 4/2/94";
41 #endif /* not lint */
42 #endif
43 
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
46 
47 #include <err.h>
48 #include <errno.h>
49 #include <stdio.h>
50 #include <string.h>
51 #include <stdlib.h>
52 #include <unistd.h>
53 
54 #include "envopts.h"
55 
56 extern char **environ;
57 
58 int	 env_verbosity;
59 
60 static void usage(void);
61 
62 /*
63  * Exit codes.
64  */
65 #define EXIT_CANCELED      125 /* Internal error prior to exec attempt. */
66 #define EXIT_CANNOT_INVOKE 126 /* Program located, but not usable. */
67 #define EXIT_ENOENT        127 /* Could not find program to exec. */
68 
69 int
70 main(int argc, char **argv)
71 {
72 	char *altpath, **ep, *p, **parg, term;
73 	char *cleanenv[1];
74 	int ch, want_clear;
75 	int rtrn;
76 
77 	altpath = NULL;
78 	want_clear = 0;
79 	term = '\n';
80 	while ((ch = getopt(argc, argv, "-0iP:S:u:v")) != -1)
81 		switch(ch) {
82 		case '-':
83 		case 'i':
84 			want_clear = 1;
85 			break;
86 		case '0':
87 			term = '\0';
88 			break;
89 		case 'P':
90 			altpath = strdup(optarg);
91 			break;
92 		case 'S':
93 			/*
94 			 * The -S option, for "split string on spaces, with
95 			 * support for some simple substitutions"...
96 			 */
97 			split_spaces(optarg, &optind, &argc, &argv);
98 			break;
99 		case 'u':
100 			if (env_verbosity)
101 				fprintf(stderr, "#env unset:\t%s\n", optarg);
102 			rtrn = unsetenv(optarg);
103 			if (rtrn == -1)
104 				err(EXIT_FAILURE, "unsetenv %s", optarg);
105 			break;
106 		case 'v':
107 			env_verbosity++;
108 			if (env_verbosity > 1)
109 				fprintf(stderr, "#env verbosity now at %d\n",
110 				    env_verbosity);
111 			break;
112 		case '?':
113 		default:
114 			usage();
115 		}
116 	if (want_clear) {
117 		environ = cleanenv;
118 		cleanenv[0] = NULL;
119 		if (env_verbosity)
120 			fprintf(stderr, "#env clearing environ\n");
121 	}
122 	for (argv += optind; *argv && (p = strchr(*argv, '=')); ++argv) {
123 		if (env_verbosity)
124 			fprintf(stderr, "#env setenv:\t%s\n", *argv);
125 		*p = '\0';
126 		rtrn = setenv(*argv, p + 1, 1);
127 		*p = '=';
128 		if (rtrn == -1)
129 			err(EXIT_FAILURE, "setenv %s", *argv);
130 	}
131 	if (*argv) {
132 		if (term == '\0')
133 			errx(EXIT_CANCELED, "cannot specify command with -0");
134 		if (altpath)
135 			search_paths(altpath, argv);
136 		if (env_verbosity) {
137 			fprintf(stderr, "#env executing:\t%s\n", *argv);
138 			for (parg = argv, argc = 0; *parg; parg++, argc++)
139 				fprintf(stderr, "#env    arg[%d]=\t'%s'\n",
140 				    argc, *parg);
141 			if (env_verbosity > 1)
142 				sleep(1);
143 		}
144 		execvp(*argv, argv);
145 		err(errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE,
146 		    "%s", *argv);
147 	}
148 	for (ep = environ; *ep; ep++)
149 		(void)printf("%s%c", *ep, term);
150 	exit(0);
151 }
152 
153 static void
154 usage(void)
155 {
156 	(void)fprintf(stderr,
157 	    "usage: env [-0iv] [-P utilpath] [-S string] [-u name]\n"
158 	    "           [name=value ...] [utility [argument ...]]\n");
159 	exit(1);
160 }
161