xref: /onnv-gate/usr/src/lib/libbc/libc/gen/common/getenv.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*      Copyright (c) 1984 AT&T */
23*0Sstevel@tonic-gate /*        All Rights Reserved   */
24*0Sstevel@tonic-gate 
25*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"  /* from S5R2 1.2 */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate /*LINTLIBRARY*/
28*0Sstevel@tonic-gate /*
29*0Sstevel@tonic-gate  *	getenv(name)
30*0Sstevel@tonic-gate  *	returns ptr to value associated with name, if any, else NULL
31*0Sstevel@tonic-gate  */
32*0Sstevel@tonic-gate #define NULL	0
33*0Sstevel@tonic-gate extern char **environ;
34*0Sstevel@tonic-gate static char *nvmatch();
35*0Sstevel@tonic-gate 
36*0Sstevel@tonic-gate char *
getenv(name)37*0Sstevel@tonic-gate getenv(name)
38*0Sstevel@tonic-gate register char *name;
39*0Sstevel@tonic-gate {
40*0Sstevel@tonic-gate 	register char *v, **p=environ;
41*0Sstevel@tonic-gate 
42*0Sstevel@tonic-gate 	if(p == NULL)
43*0Sstevel@tonic-gate 		return(NULL);
44*0Sstevel@tonic-gate 	while(*p != NULL)
45*0Sstevel@tonic-gate 		if((v = nvmatch(name, *p++)) != NULL)
46*0Sstevel@tonic-gate 			return(v);
47*0Sstevel@tonic-gate 	return(NULL);
48*0Sstevel@tonic-gate }
49*0Sstevel@tonic-gate 
50*0Sstevel@tonic-gate /*
51*0Sstevel@tonic-gate  *	s1 is either name, or name=value
52*0Sstevel@tonic-gate  *	s2 is name=value
53*0Sstevel@tonic-gate  *	if names match, return value of s2, else NULL
54*0Sstevel@tonic-gate  *	used for environment searching: see getenv
55*0Sstevel@tonic-gate  */
56*0Sstevel@tonic-gate 
57*0Sstevel@tonic-gate static char *
nvmatch(s1,s2)58*0Sstevel@tonic-gate nvmatch(s1, s2)
59*0Sstevel@tonic-gate register char *s1, *s2;
60*0Sstevel@tonic-gate {
61*0Sstevel@tonic-gate 	while(*s1 == *s2++)
62*0Sstevel@tonic-gate 		if(*s1++ == '=')
63*0Sstevel@tonic-gate 			return(s2);
64*0Sstevel@tonic-gate 	if(*s1 == '\0' && *(s2-1) == '=')
65*0Sstevel@tonic-gate 		return(s2);
66*0Sstevel@tonic-gate 	return(NULL);
67*0Sstevel@tonic-gate }
68