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      1 /*	$NetBSD: putenv.c,v 1.21 2015/01/20 18:31:25 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1988, 1993
      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 #include <sys/cdefs.h>
     33 #if defined(LIBC_SCCS) && !defined(lint)
     34 #if 0
     35 static char sccsid[] = "@(#)putenv.c	8.2 (Berkeley) 3/27/94";
     36 #else
     37 __RCSID("$NetBSD: putenv.c,v 1.21 2015/01/20 18:31:25 christos Exp $");
     38 #endif
     39 #endif /* LIBC_SCCS and not lint */
     40 
     41 #include "namespace.h"
     42 
     43 #include <assert.h>
     44 #include <errno.h>
     45 #include <stdlib.h>
     46 #include <string.h>
     47 
     48 #include "env.h"
     49 #include "local.h"
     50 
     51 int
     52 putenv(char *str)
     53 {
     54 	size_t l_name;
     55 	int rv;
     56 
     57 	_DIAGASSERT(str != NULL);
     58 
     59 	l_name = __envvarnamelen(str, true);
     60 	if (l_name == 0) {
     61 		errno = EINVAL;
     62 		return -1;
     63 	}
     64 
     65 	rv = -1;
     66 	if (__writelockenv()) {
     67 		ssize_t offset;
     68 
     69 		offset = __getenvslot(str, l_name, true);
     70 		if (offset != -1) {
     71 			if (environ[offset] != NULL)
     72 				__freeenvvar(environ[offset]);
     73 			environ[offset] = str;
     74 
     75 			rv = 0;
     76 		}
     77 
     78 		(void)__unlockenv();
     79 	}
     80 
     81 	return rv;
     82 }
     83