xref: /freebsd-14.2/usr.bin/env/env.c (revision 08e8554c)
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 #include <sys/types.h>
46 
47 #include <err.h>
48 #include <errno.h>
49 #include <login_cap.h>
50 #include <pwd.h>
51 #include <stdbool.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56 
57 #include "envopts.h"
58 
59 extern char **environ;
60 
61 int	 env_verbosity;
62 
63 static void usage(void) __dead2;
64 
65 /*
66  * Exit codes.
67  */
68 #define EXIT_CANCELED      125 /* Internal error prior to exec attempt. */
69 #define EXIT_CANNOT_INVOKE 126 /* Program located, but not usable. */
70 #define EXIT_ENOENT        127 /* Could not find program to exec. */
71 
72 int
main(int argc,char ** argv)73 main(int argc, char **argv)
74 {
75 	char *altpath, *altwd, **ep, *p, **parg, term;
76 	char *cleanenv[1];
77 	char *login_class, *login_name;
78 	struct passwd *pw;
79 	login_cap_t *lc;
80 	bool login_as_user;
81 	uid_t uid;
82 	int ch, want_clear;
83 	int rtrn;
84 
85 	altpath = NULL;
86 	altwd = NULL;
87 	login_class = NULL;
88 	login_name = NULL;
89 	pw = NULL;
90 	lc = NULL;
91 	login_as_user = false;
92 	want_clear = 0;
93 	term = '\n';
94 	while ((ch = getopt(argc, argv, "-0C:iL:P:S:U:u:v")) != -1)
95 		switch(ch) {
96 		case '-':
97 		case 'i':
98 			want_clear = 1;
99 			break;
100 		case '0':
101 			term = '\0';
102 			break;
103 		case 'C':
104 			altwd = optarg;
105 			break;
106 		case 'U':
107 			login_as_user = true;
108 			/* FALLTHROUGH */
109 		case 'L':
110 			login_name = optarg;
111 			break;
112 		case 'P':
113 			altpath = optarg;
114 			break;
115 		case 'S':
116 			/*
117 			 * The -S option, for "split string on spaces, with
118 			 * support for some simple substitutions"...
119 			 */
120 			split_spaces(optarg, &optind, &argc, &argv);
121 			break;
122 		case 'u':
123 			if (env_verbosity)
124 				fprintf(stderr, "#env unset:\t%s\n", optarg);
125 			rtrn = unsetenv(optarg);
126 			if (rtrn == -1)
127 				err(EXIT_FAILURE, "unsetenv %s", optarg);
128 			break;
129 		case 'v':
130 			env_verbosity++;
131 			if (env_verbosity > 1)
132 				fprintf(stderr, "#env verbosity now at %d\n",
133 				    env_verbosity);
134 			break;
135 		case '?':
136 		default:
137 			usage();
138 		}
139 	if (want_clear) {
140 		environ = cleanenv;
141 		cleanenv[0] = NULL;
142 		if (env_verbosity)
143 			fprintf(stderr, "#env clearing environ\n");
144 	}
145 	if (login_name != NULL) {
146 		login_class = strchr(login_name, '/');
147 		if (login_class)
148 			*login_class++ = '\0';
149 		if (*login_name != '\0' && strcmp(login_name, "-") != 0) {
150 			pw = getpwnam(login_name);
151 			if (pw == NULL) {
152 				char *endp = NULL;
153 				errno = 0;
154 				uid = strtoul(login_name, &endp, 10);
155 				if (errno == 0 && *endp == '\0')
156 					pw = getpwuid(uid);
157 			}
158 			if (pw == NULL)
159 				errx(EXIT_FAILURE, "no such user: %s", login_name);
160 		}
161 		/*
162 		 * Note that it is safe for pw to be null here; the libutil
163 		 * code handles that, bypassing substitution of $ and using
164 		 * the class "default" if no class name is given either.
165 		 */
166 		if (login_class != NULL) {
167 			lc = login_getclass(login_class);
168 			if (lc == NULL)
169 				errx(EXIT_FAILURE, "no such login class: %s",
170 				    login_class);
171 		} else {
172 			lc = login_getpwclass(pw);
173 			if (lc == NULL)
174 				errx(EXIT_FAILURE, "login_getpwclass failed");
175 		}
176 
177 		/*
178 		 * This is not done with setusercontext() because that will
179 		 * try and use ~/.login_conf even when we don't want it to.
180 		 */
181 		setclassenvironment(lc, pw, 1);
182 		setclassenvironment(lc, pw, 0);
183 		if (login_as_user) {
184 			login_close(lc);
185 			if ((lc = login_getuserclass(pw)) != NULL) {
186 				setclassenvironment(lc, pw, 1);
187 				setclassenvironment(lc, pw, 0);
188 			}
189 		}
190 		endpwent();
191 		if (lc != NULL)
192 			login_close(lc);
193 	}
194 	for (argv += optind; *argv && (p = strchr(*argv, '=')); ++argv) {
195 		if (env_verbosity)
196 			fprintf(stderr, "#env setenv:\t%s\n", *argv);
197 		*p = '\0';
198 		rtrn = setenv(*argv, p + 1, 1);
199 		*p = '=';
200 		if (rtrn == -1)
201 			err(EXIT_FAILURE, "setenv %s", *argv);
202 	}
203 	if (*argv) {
204 		if (term == '\0')
205 			errx(EXIT_CANCELED, "cannot specify command with -0");
206 		if (altwd && chdir(altwd) != 0)
207 			err(EXIT_CANCELED, "cannot change directory to '%s'",
208 			    altwd);
209 		if (altpath)
210 			search_paths(altpath, argv);
211 		if (env_verbosity) {
212 			fprintf(stderr, "#env executing:\t%s\n", *argv);
213 			for (parg = argv, argc = 0; *parg; parg++, argc++)
214 				fprintf(stderr, "#env    arg[%d]=\t'%s'\n",
215 				    argc, *parg);
216 			if (env_verbosity > 1)
217 				sleep(1);
218 		}
219 		execvp(*argv, argv);
220 		err(errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE,
221 		    "%s", *argv);
222 	} else {
223 		if (altwd)
224 			errx(EXIT_CANCELED, "must specify command with -C");
225 		if (altpath)
226 			errx(EXIT_CANCELED, "must specify command with -P");
227 	}
228 	for (ep = environ; *ep; ep++)
229 		(void)printf("%s%c", *ep, term);
230 	if (fflush(stdout) != 0)
231 		err(1, "stdout");
232 	exit(0);
233 }
234 
235 static void
usage(void)236 usage(void)
237 {
238 	(void)fprintf(stderr,
239 	    "usage: env [-0iv] [-C workdir] [-L|-U user[/class]] [-P utilpath] [-S string]\n"
240 	    "           [-u name] [name=value ...] [utility [argument ...]]\n");
241 	exit(1);
242 }
243