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env.c revision 1.23 
      1 /*	$NetBSD: env.c,v 1.23 2020/02/08 11:02:07 kamil 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 1.23 2020/02/08 11:02:07 kamil 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, "-0iu:")) != -1)
     66 		switch((char)ch) {
     67 		case '0':
     68 			term = '\0';
     69 			break;
     70 		case '-':			/* obsolete */
     71 		case 'i':
     72 			environ = cleanenv;
     73 			cleanenv[0] = NULL;
     74 			break;
     75 		case 'u':
     76 			if (unsetenv(optarg) == -1)
     77 				errx(EXIT_FAILURE, "unsetenv %s", optarg);
     78 			break;
     79 		case '?':
     80 		default:
     81 			usage();
     82 		}
     83 
     84 	for (argv += optind; *argv && strchr(*argv, '=') != NULL; ++argv)
     85 		(void)putenv(*argv);
     86 
     87 	if (*argv) {
     88 		/* return 127 if the command to be run could not be found; 126
     89 		   if the command was found but could not be invoked; 125 if
     90 		   -0 was specified with utility.*/
     91 
     92 		if (term == '\0')
     93 			errx(125, "cannot specify command with -0");
     94 
     95 		(void)execvp(*argv, argv);
     96 		err((errno == ENOENT) ? 127 : 126, "%s", *argv);
     97 		/* NOTREACHED */
     98 	}
     99 
    100 	for (ep = environ; *ep; ep++)
    101 		(void)printf("%s%c", *ep, term);
    102 
    103 	exit(0);
    104 }
    105 
    106 static void
    107 usage(void)
    108 {
    109 	(void)fprintf(stderr,
    110 	    "Usage: %s [-0i] [-u name] [name=value ...] [command]\n",
    111 	    getprogname());
    112 	exit(1);
    113 }
    114