xref: /freebsd/usr.bin/env/env.c (revision 5b31cc94b10d4bb7109c6b27940a0fc76a44a331)
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 #endif
40 
41 #include <sys/cdefs.h>
42 #include <sys/types.h>
43 
44 #include <err.h>
45 #include <errno.h>
46 #include <login_cap.h>
47 #include <pwd.h>
48 #include <stdbool.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <string.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) __dead2;
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 	char *login_class, *login_name;
75 	struct passwd *pw;
76 	login_cap_t *lc;
77 	bool login_as_user;
78 	uid_t uid;
79 	int ch, want_clear;
80 	int rtrn;
81 
82 	altpath = NULL;
83 	login_class = NULL;
84 	login_name = NULL;
85 	pw = NULL;
86 	lc = NULL;
87 	login_as_user = false;
88 	want_clear = 0;
89 	term = '\n';
90 	while ((ch = getopt(argc, argv, "-0iL:P:S:U:u:v")) != -1)
91 		switch(ch) {
92 		case '-':
93 		case 'i':
94 			want_clear = 1;
95 			break;
96 		case '0':
97 			term = '\0';
98 			break;
99 		case 'U':
100 			login_as_user = true;
101 			/* FALLTHROUGH */
102 		case 'L':
103 			login_name = optarg;
104 			break;
105 		case 'P':
106 			altpath = strdup(optarg);
107 			break;
108 		case 'S':
109 			/*
110 			 * The -S option, for "split string on spaces, with
111 			 * support for some simple substitutions"...
112 			 */
113 			split_spaces(optarg, &optind, &argc, &argv);
114 			break;
115 		case 'u':
116 			if (env_verbosity)
117 				fprintf(stderr, "#env unset:\t%s\n", optarg);
118 			rtrn = unsetenv(optarg);
119 			if (rtrn == -1)
120 				err(EXIT_FAILURE, "unsetenv %s", optarg);
121 			break;
122 		case 'v':
123 			env_verbosity++;
124 			if (env_verbosity > 1)
125 				fprintf(stderr, "#env verbosity now at %d\n",
126 				    env_verbosity);
127 			break;
128 		case '?':
129 		default:
130 			usage();
131 		}
132 	if (want_clear) {
133 		environ = cleanenv;
134 		cleanenv[0] = NULL;
135 		if (env_verbosity)
136 			fprintf(stderr, "#env clearing environ\n");
137 	}
138 	if (login_name != NULL) {
139 		login_class = strchr(login_name, '/');
140 		if (login_class)
141 			*login_class++ = '\0';
142 		if (*login_name != '\0' && strcmp(login_name, "-") != 0) {
143 			pw = getpwnam(login_name);
144 			if (pw == NULL) {
145 				char *endp = NULL;
146 				errno = 0;
147 				uid = strtoul(login_name, &endp, 10);
148 				if (errno == 0 && *endp == '\0')
149 					pw = getpwuid(uid);
150 			}
151 			if (pw == NULL)
152 				errx(EXIT_FAILURE, "no such user: %s", login_name);
153 		}
154 		/*
155 		 * Note that it is safe for pw to be null here; the libutil
156 		 * code handles that, bypassing substitution of $ and using
157 		 * the class "default" if no class name is given either.
158 		 */
159 		if (login_class != NULL) {
160 			lc = login_getclass(login_class);
161 			if (lc == NULL)
162 				errx(EXIT_FAILURE, "no such login class: %s",
163 				    login_class);
164 		} else {
165 			lc = login_getpwclass(pw);
166 			if (lc == NULL)
167 				errx(EXIT_FAILURE, "login_getpwclass failed");
168 		}
169 
170 		/*
171 		 * This is not done with setusercontext() because that will
172 		 * try and use ~/.login_conf even when we don't want it to.
173 		 */
174 		setclassenvironment(lc, pw, 1);
175 		setclassenvironment(lc, pw, 0);
176 		if (login_as_user) {
177 			login_close(lc);
178 			if ((lc = login_getuserclass(pw)) != NULL) {
179 				setclassenvironment(lc, pw, 1);
180 				setclassenvironment(lc, pw, 0);
181 			}
182 		}
183 		endpwent();
184 		if (lc != NULL)
185 			login_close(lc);
186 	}
187 	for (argv += optind; *argv && (p = strchr(*argv, '=')); ++argv) {
188 		if (env_verbosity)
189 			fprintf(stderr, "#env setenv:\t%s\n", *argv);
190 		*p = '\0';
191 		rtrn = setenv(*argv, p + 1, 1);
192 		*p = '=';
193 		if (rtrn == -1)
194 			err(EXIT_FAILURE, "setenv %s", *argv);
195 	}
196 	if (*argv) {
197 		if (term == '\0')
198 			errx(EXIT_CANCELED, "cannot specify command with -0");
199 		if (altpath)
200 			search_paths(altpath, argv);
201 		if (env_verbosity) {
202 			fprintf(stderr, "#env executing:\t%s\n", *argv);
203 			for (parg = argv, argc = 0; *parg; parg++, argc++)
204 				fprintf(stderr, "#env    arg[%d]=\t'%s'\n",
205 				    argc, *parg);
206 			if (env_verbosity > 1)
207 				sleep(1);
208 		}
209 		execvp(*argv, argv);
210 		err(errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE,
211 		    "%s", *argv);
212 	}
213 	for (ep = environ; *ep; ep++)
214 		(void)printf("%s%c", *ep, term);
215 	exit(0);
216 }
217 
218 static void
219 usage(void)
220 {
221 	(void)fprintf(stderr,
222 	    "usage: env [-0iv] [-L|-U user[/class]] [-P utilpath] [-S string] [-u name]\n"
223 	    "           [name=value ...] [utility [argument ...]]\n");
224 	exit(1);
225 }
226