xref: /freebsd/usr.bin/env/env.c (revision e8d8bef961a50d4dc22501cde4fb9fb0be1b2532)
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 		if (*login_name != '\0' && strcmp(login_name, "-") != 0) {
148 			pw = getpwnam(login_name);
149 			if (pw == NULL) {
150 				char *endp = NULL;
151 				errno = 0;
152 				uid = strtoul(login_name, &endp, 10);
153 				if (errno == 0 && *endp == '\0')
154 					pw = getpwuid(uid);
155 			}
156 			if (pw == NULL)
157 				errx(EXIT_FAILURE, "no such user: %s", login_name);
158 		}
159 		/*
160 		 * Note that it is safe for pw to be null here; the libutil
161 		 * code handles that, bypassing substitution of $ and using
162 		 * the class "default" if no class name is given either.
163 		 */
164 		if (login_class != NULL) {
165 			lc = login_getclass(login_class);
166 			if (lc == NULL)
167 				errx(EXIT_FAILURE, "no such login class: %s",
168 				    login_class);
169 		} else {
170 			lc = login_getpwclass(pw);
171 			if (lc == NULL)
172 				errx(EXIT_FAILURE, "login_getpwclass failed");
173 		}
174 
175 		/*
176 		 * This is not done with setusercontext() because that will
177 		 * try and use ~/.login_conf even when we don't want it to.
178 		 */
179 		setclassenvironment(lc, pw, 1);
180 		setclassenvironment(lc, pw, 0);
181 		if (login_as_user) {
182 			login_close(lc);
183 			if ((lc = login_getuserclass(pw)) != NULL) {
184 				setclassenvironment(lc, pw, 1);
185 				setclassenvironment(lc, pw, 0);
186 			}
187 		}
188 		endpwent();
189 		if (lc != NULL)
190 			login_close(lc);
191 	}
192 	for (argv += optind; *argv && (p = strchr(*argv, '=')); ++argv) {
193 		if (env_verbosity)
194 			fprintf(stderr, "#env setenv:\t%s\n", *argv);
195 		*p = '\0';
196 		rtrn = setenv(*argv, p + 1, 1);
197 		*p = '=';
198 		if (rtrn == -1)
199 			err(EXIT_FAILURE, "setenv %s", *argv);
200 	}
201 	if (*argv) {
202 		if (term == '\0')
203 			errx(EXIT_CANCELED, "cannot specify command with -0");
204 		if (altpath)
205 			search_paths(altpath, argv);
206 		if (env_verbosity) {
207 			fprintf(stderr, "#env executing:\t%s\n", *argv);
208 			for (parg = argv, argc = 0; *parg; parg++, argc++)
209 				fprintf(stderr, "#env    arg[%d]=\t'%s'\n",
210 				    argc, *parg);
211 			if (env_verbosity > 1)
212 				sleep(1);
213 		}
214 		execvp(*argv, argv);
215 		err(errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE,
216 		    "%s", *argv);
217 	}
218 	for (ep = environ; *ep; ep++)
219 		(void)printf("%s%c", *ep, term);
220 	exit(0);
221 }
222 
223 static void
224 usage(void)
225 {
226 	(void)fprintf(stderr,
227 	    "usage: env [-0iv] [-L|-U user[/class]] [-P utilpath] [-S string] [-u name]\n"
228 	    "           [name=value ...] [utility [argument ...]]\n");
229 	exit(1);
230 }
231