xref: /freebsd/usr.bin/env/env.c (revision 3cbb4cc200f8a0ad7ed08233425ea54524a21f1c)
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 <sys/types.h>
48 
49 #include <err.h>
50 #include <errno.h>
51 #include <login_cap.h>
52 #include <pwd.h>
53 #include <stdbool.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <unistd.h>
58 
59 #include "envopts.h"
60 
61 extern char **environ;
62 
63 int	 env_verbosity;
64 
65 static void usage(void);
66 
67 /*
68  * Exit codes.
69  */
70 #define EXIT_CANCELED      125 /* Internal error prior to exec attempt. */
71 #define EXIT_CANNOT_INVOKE 126 /* Program located, but not usable. */
72 #define EXIT_ENOENT        127 /* Could not find program to exec. */
73 
74 int
75 main(int argc, char **argv)
76 {
77 	char *altpath, **ep, *p, **parg, term;
78 	char *cleanenv[1];
79 	char *login_class, *login_name;
80 	struct passwd *pw;
81 	login_cap_t *lc;
82 	bool login_as_user;
83 	uid_t uid;
84 	int ch, want_clear;
85 	int rtrn;
86 
87 	altpath = NULL;
88 	login_class = NULL;
89 	login_name = NULL;
90 	pw = NULL;
91 	lc = NULL;
92 	login_as_user = false;
93 	want_clear = 0;
94 	term = '\n';
95 	while ((ch = getopt(argc, argv, "-0iL:P:S:U:u:v")) != -1)
96 		switch(ch) {
97 		case '-':
98 		case 'i':
99 			want_clear = 1;
100 			break;
101 		case '0':
102 			term = '\0';
103 			break;
104 		case 'U':
105 			login_as_user = true;
106 			/* FALLTHROUGH */
107 		case 'L':
108 			login_name = optarg;
109 			break;
110 		case 'P':
111 			altpath = strdup(optarg);
112 			break;
113 		case 'S':
114 			/*
115 			 * The -S option, for "split string on spaces, with
116 			 * support for some simple substitutions"...
117 			 */
118 			split_spaces(optarg, &optind, &argc, &argv);
119 			break;
120 		case 'u':
121 			if (env_verbosity)
122 				fprintf(stderr, "#env unset:\t%s\n", optarg);
123 			rtrn = unsetenv(optarg);
124 			if (rtrn == -1)
125 				err(EXIT_FAILURE, "unsetenv %s", optarg);
126 			break;
127 		case 'v':
128 			env_verbosity++;
129 			if (env_verbosity > 1)
130 				fprintf(stderr, "#env verbosity now at %d\n",
131 				    env_verbosity);
132 			break;
133 		case '?':
134 		default:
135 			usage();
136 		}
137 	if (want_clear) {
138 		environ = cleanenv;
139 		cleanenv[0] = NULL;
140 		if (env_verbosity)
141 			fprintf(stderr, "#env clearing environ\n");
142 	}
143 	if (login_name != NULL) {
144 		login_class = strchr(login_name, '/');
145 		if (login_class)
146 			*login_class++ = '\0';
147 		pw = getpwnam(login_name);
148 		if (pw == NULL) {
149 			char *endp = NULL;
150 			errno = 0;
151 			uid = strtoul(login_name, &endp, 10);
152 			if (errno == 0 && *endp == '\0')
153 				pw = getpwuid(uid);
154 		}
155 		if (pw == NULL)
156 			errx(EXIT_FAILURE, "no such user: %s", login_name);
157 		if (login_class != NULL) {
158 			lc = login_getclass(login_class);
159 			if (lc == NULL)
160 				errx(EXIT_FAILURE, "no such login class: %s",
161 				    login_class);
162 		} else {
163 			lc = login_getpwclass(pw);
164 			if (lc == NULL)
165 				errx(EXIT_FAILURE, "login_getpwclass failed");
166 		}
167 
168 		/*
169 		 * This is not done with setusercontext() because that will
170 		 * try and use ~/.login_conf even when we don't want it to.
171 		 */
172 		setclassenvironment(lc, pw, 1);
173 		setclassenvironment(lc, pw, 0);
174 		if (login_as_user) {
175 			login_close(lc);
176 			if ((lc = login_getuserclass(pw)) != NULL) {
177 				setclassenvironment(lc, pw, 1);
178 				setclassenvironment(lc, pw, 0);
179 			}
180 		}
181 		endpwent();
182 		if (lc != NULL)
183 			login_close(lc);
184 	}
185 	for (argv += optind; *argv && (p = strchr(*argv, '=')); ++argv) {
186 		if (env_verbosity)
187 			fprintf(stderr, "#env setenv:\t%s\n", *argv);
188 		*p = '\0';
189 		rtrn = setenv(*argv, p + 1, 1);
190 		*p = '=';
191 		if (rtrn == -1)
192 			err(EXIT_FAILURE, "setenv %s", *argv);
193 	}
194 	if (*argv) {
195 		if (term == '\0')
196 			errx(EXIT_CANCELED, "cannot specify command with -0");
197 		if (altpath)
198 			search_paths(altpath, argv);
199 		if (env_verbosity) {
200 			fprintf(stderr, "#env executing:\t%s\n", *argv);
201 			for (parg = argv, argc = 0; *parg; parg++, argc++)
202 				fprintf(stderr, "#env    arg[%d]=\t'%s'\n",
203 				    argc, *parg);
204 			if (env_verbosity > 1)
205 				sleep(1);
206 		}
207 		execvp(*argv, argv);
208 		err(errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE,
209 		    "%s", *argv);
210 	}
211 	for (ep = environ; *ep; ep++)
212 		(void)printf("%s%c", *ep, term);
213 	exit(0);
214 }
215 
216 static void
217 usage(void)
218 {
219 	(void)fprintf(stderr,
220 	    "usage: env [-0iv] [-L|-U user[/class]] [-P utilpath] [-S string] [-u name]\n"
221 	    "           [name=value ...] [utility [argument ...]]\n");
222 	exit(1);
223 }
224