xref: /netbsd-src/usr.bin/env/env.c (revision b4519c5b39ea2ac24cca20cbfc9f67a6716dcc78)
1 /*	$NetBSD: env.c,v 1.24 2024/10/28 11:30:37 kim Exp $	*/
2 /*
3  * Copyright (c) 1988, 1993, 1994
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 #ifndef lint
33 __COPYRIGHT("@(#) Copyright (c) 1988, 1993, 1994\
34  The Regents of the University of California.  All rights reserved.");
35 #endif /* not lint */
36 
37 #ifndef lint
38 /*static char sccsid[] = "@(#)env.c	8.3 (Berkeley) 4/2/94";*/
39 __RCSID("$NetBSD: env.c,v 1.24 2024/10/28 11:30:37 kim Exp $");
40 #endif /* not lint */
41 
42 #include <err.h>
43 #include <stdio.h>
44 #include <string.h>
45 #include <stdlib.h>
46 #include <unistd.h>
47 #include <locale.h>
48 #include <errno.h>
49 
50 static void usage(void) __dead;
51 
52 extern char **environ;
53 
54 int
55 main(int argc, char **argv)
56 {
57 	char **ep, term;
58 	char *cleanenv[1];
59 	int ch;
60 
61 	setprogname(*argv);
62 	(void)setlocale(LC_ALL, "");
63 
64 	term = '\n';
65 	while ((ch = getopt(argc, argv, "-0C:iu:")) != -1)
66 		switch((char)ch) {
67 		case '0':
68 			term = '\0';
69 			break;
70 		case 'C':
71 			if (chdir(optarg) == -1)
72 				err(EXIT_FAILURE, "chdir '%s'", optarg);
73 			break;
74 		case '-':			/* obsolete */
75 		case 'i':
76 			environ = cleanenv;
77 			cleanenv[0] = NULL;
78 			break;
79 		case 'u':
80 			if (unsetenv(optarg) == -1)
81 				err(EXIT_FAILURE, "unsetenv '%s'", optarg);
82 			break;
83 		case '?':
84 		default:
85 			usage();
86 		}
87 
88 	for (argv += optind; *argv && strchr(*argv, '=') != NULL; ++argv)
89 		(void)putenv(*argv);
90 
91 	if (*argv) {
92 		/* return 127 if the command to be run could not be found; 126
93 		   if the command was found but could not be invoked; 125 if
94 		   -0 was specified with utility.*/
95 
96 		if (term == '\0')
97 			errx(125, "cannot specify command with -0");
98 
99 		(void)execvp(*argv, argv);
100 		err((errno == ENOENT) ? 127 : 126, "%s", *argv);
101 		/* NOTREACHED */
102 	}
103 
104 	for (ep = environ; *ep; ep++)
105 		(void)printf("%s%c", *ep, term);
106 
107 	exit(0);
108 }
109 
110 static void
111 usage(void)
112 {
113 	(void)fprintf(stderr,
114 	    "Usage: %s [-0i] [-C dir] [-u name] [name=value ...] [command]\n",
115 	    getprogname());
116 	exit(1);
117 }
118