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getenv.c revision 1.9
      1  1.9     perry /*	$NetBSD: getenv.c,v 1.9 1998/01/30 23:37:55 perry Exp $	*/
      2  1.6   thorpej 
      3  1.1       cgd /*
      4  1.9     perry  * Copyright (c) 1987, 1993
      5  1.9     perry  *	The Regents of the University of California.  All rights reserved.
      6  1.1       cgd  *
      7  1.1       cgd  * Redistribution and use in source and binary forms, with or without
      8  1.1       cgd  * modification, are permitted provided that the following conditions
      9  1.1       cgd  * are met:
     10  1.1       cgd  * 1. Redistributions of source code must retain the above copyright
     11  1.1       cgd  *    notice, this list of conditions and the following disclaimer.
     12  1.1       cgd  * 2. Redistributions in binary form must reproduce the above copyright
     13  1.1       cgd  *    notice, this list of conditions and the following disclaimer in the
     14  1.1       cgd  *    documentation and/or other materials provided with the distribution.
     15  1.1       cgd  * 3. All advertising materials mentioning features or use of this software
     16  1.1       cgd  *    must display the following acknowledgement:
     17  1.1       cgd  *	This product includes software developed by the University of
     18  1.1       cgd  *	California, Berkeley and its contributors.
     19  1.1       cgd  * 4. Neither the name of the University nor the names of its contributors
     20  1.1       cgd  *    may be used to endorse or promote products derived from this software
     21  1.1       cgd  *    without specific prior written permission.
     22  1.1       cgd  *
     23  1.1       cgd  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  1.1       cgd  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  1.1       cgd  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  1.1       cgd  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  1.1       cgd  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  1.1       cgd  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  1.1       cgd  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  1.1       cgd  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  1.1       cgd  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  1.1       cgd  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  1.1       cgd  * SUCH DAMAGE.
     34  1.1       cgd  */
     35  1.1       cgd 
     36  1.8  christos #include <sys/cdefs.h>
     37  1.1       cgd #if defined(LIBC_SCCS) && !defined(lint)
     38  1.6   thorpej #if 0
     39  1.9     perry static char sccsid[] = "@(#)getenv.c	8.1 (Berkeley) 6/4/93";
     40  1.6   thorpej #else
     41  1.9     perry __RCSID("$NetBSD: getenv.c,v 1.9 1998/01/30 23:37:55 perry Exp $");
     42  1.6   thorpej #endif
     43  1.1       cgd #endif /* LIBC_SCCS and not lint */
     44  1.1       cgd 
     45  1.1       cgd #include <stdlib.h>
     46  1.1       cgd #include <string.h>
     47  1.8  christos #include "local.h"
     48  1.1       cgd 
     49  1.1       cgd /*
     50  1.1       cgd  * getenv --
     51  1.1       cgd  *	Returns ptr to value associated with name, if any, else NULL.
     52  1.1       cgd  */
     53  1.1       cgd char *
     54  1.1       cgd getenv(name)
     55  1.1       cgd 	const char *name;
     56  1.1       cgd {
     57  1.1       cgd 	int offset;
     58  1.1       cgd 
     59  1.9     perry 	return (__findenv(name, &offset));
     60  1.1       cgd }
     61  1.1       cgd 
     62  1.1       cgd /*
     63  1.4       jtc  * __findenv --
     64  1.1       cgd  *	Returns pointer to value associated with name, if any, else NULL.
     65  1.1       cgd  *	Sets offset to be the offset of the name/value combination in the
     66  1.1       cgd  *	environmental array, for use by setenv(3) and unsetenv(3).
     67  1.1       cgd  *	Explicitly removes '=' in argument name.
     68  1.1       cgd  *
     69  1.1       cgd  *	This routine *should* be a static; don't use it.
     70  1.1       cgd  */
     71  1.1       cgd char *
     72  1.4       jtc __findenv(name, offset)
     73  1.7       cgd 	register const char *name;
     74  1.1       cgd 	int *offset;
     75  1.1       cgd {
     76  1.1       cgd 	extern char **environ;
     77  1.1       cgd 	register int len;
     78  1.9     perry 	register const char *np;
     79  1.9     perry 	register char **p, *c;
     80  1.1       cgd 
     81  1.9     perry 	if (name == NULL || environ == NULL)
     82  1.9     perry 		return (NULL);
     83  1.9     perry 	for (np = name; *np && *np != '='; ++np)
     84  1.9     perry 		continue;
     85  1.9     perry 	len = np - name;
     86  1.9     perry 	for (p = environ; (c = *p) != NULL; ++p)
     87  1.9     perry 		if (strncmp(c, name, len) == 0 && c[len] == '=') {
     88  1.9     perry 			*offset = p - environ;
     89  1.9     perry 			return (c + len + 1);
     90  1.9     perry 		}
     91  1.9     perry 	return (NULL);
     92  1.1       cgd }
     93