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env.c revision 1.2 
      1 /*
      2  * Copyright (c) 1988 The Regents of the University of California.
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  */
     33 
     34 #ifndef lint
     35 char copyright[] =
     36 "@(#) Copyright (c) 1988 The Regents of the University of California.\n\
     37  All rights reserved.\n";
     38 #endif /* not lint */
     39 
     40 #ifndef lint
     41 static char sccsid[] = "@(#)env.c	5.3 (Berkeley) 6/1/90";
     42 #endif /* not lint */
     43 
     44 #include <stdio.h>
     45 #include <string.h>
     46 #include <errno.h>
     47 
     48 static void usage();
     49 
     50 main(argc, argv)
     51 	int argc;
     52 	char **argv;
     53 {
     54 	extern char **environ;
     55 	extern int errno, optind;
     56 	register char **ep, *p;
     57 	char *cleanenv[1];
     58 	int ch;
     59 
     60 	while ((ch = getopt(argc, argv, "-i")) != EOF)
     61 		switch((char)ch) {
     62 		case '-':			/* obsolete */
     63 		case 'i':
     64 			environ = cleanenv;
     65 			cleanenv[0] = NULL;
     66 			break;
     67 		case '?':
     68 		default:
     69 			usage();
     70 		}
     71 
     72 	for (argv += optind; *argv && (p = index(*argv, '=')); ++argv)
     73 		(void)setenv(*argv, ++p, 1);
     74 
     75 	if (*argv) {
     76 		/* return 127 if the command to be run could not be found; 126
     77 		   if the command was was found but could not be invoked */
     78 		int status;
     79 
     80 		execvp(*argv, argv);
     81 		status = (errno == ENOENT) ? 127 : 126;
     82 		(void)fprintf(stderr, "env: %s: %s\n", *argv, strerror(errno));
     83 		exit(status);
     84 	}
     85 
     86 	for (ep = environ; *ep; ep++)
     87 		(void)printf("%s\n", *ep);
     88 
     89 	exit(0);
     90 }
     91 
     92 static void
     93 usage ()
     94 {
     95 	(void) fprintf(stderr, "usage: env [-i] [name=value ...] [command]\n");
     96 	exit (1);
     97 }
     98