1 /*	$NetBSD: putenv.c,v 1.1.1.1 2011/04/13 18:15:42 elric Exp $	*/
2 
3 /*
4  * Copyright (c) 1995, 1996, 1997 Kungliga Tekniska Högskolan
5  * (Royal Institute of Technology, Stockholm, Sweden).
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * 3. Neither the name of the Institute nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <config.h>
37 
38 #include <stdlib.h>
39 
40 #if !HAVE_DECL_ENVIRON
41 extern char **environ;
42 #endif
43 
44 /*
45  * putenv --
46  *	String points to a string of the form name=value.
47  *
48  *      Makes the value of the environment variable name equal to
49  *      value by altering an existing variable or creating a new one.
50  */
51 
52 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
putenv(const char * string)53 putenv(const char *string)
54 {
55     int i;
56     const char *eq = (const char *)strchr(string, '=');
57     int len;
58 
59     if (eq == NULL)
60 	return 1;
61     len = eq - string;
62 
63     if(environ == NULL) {
64 	environ = malloc(sizeof(char*));
65 	if(environ == NULL)
66 	    return 1;
67 	environ[0] = NULL;
68     }
69 
70     for(i = 0; environ[i] != NULL; i++)
71 	if(strncmp(string, environ[i], len) == 0) {
72 	    environ[i] = string;
73 	    return 0;
74 	}
75     environ = realloc(environ, sizeof(char*) * (i + 2));
76     if(environ == NULL)
77 	return 1;
78     environ[i]   = string;
79     environ[i+1] = NULL;
80     return 0;
81 }
82