xref: /freebsd/crypto/heimdal/lib/roken/putenv.c (revision 6a068746777241722b2b32c5d0bc443a2a64d80b)
1 /*
2  * Copyright (c) 1995, 1996, 1997 Kungliga Tekniska Högskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * 3. Neither the name of the Institute 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 INSTITUTE 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 INSTITUTE 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 #include <config.h>
35 
36 #include <stdlib.h>
37 
38 #if !HAVE_DECL_ENVIRON
39 extern char **environ;
40 #endif
41 
42 /*
43  * putenv --
44  *	String points to a string of the form name=value.
45  *
46  *      Makes the value of the environment variable name equal to
47  *      value by altering an existing variable or creating a new one.
48  */
49 
50 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
putenv(const char * string)51 putenv(const char *string)
52 {
53     int i;
54     const char *eq = (const char *)strchr(string, '=');
55     int len;
56 
57     if (eq == NULL)
58 	return 1;
59     len = eq - string;
60 
61     if(environ == NULL) {
62 	environ = malloc(sizeof(char*));
63 	if(environ == NULL)
64 	    return 1;
65 	environ[0] = NULL;
66     }
67 
68     for(i = 0; environ[i] != NULL; i++)
69 	if(strncmp(string, environ[i], len) == 0) {
70 	    environ[i] = string;
71 	    return 0;
72 	}
73     environ = realloc(environ, sizeof(char*) * (i + 2));
74     if(environ == NULL)
75 	return 1;
76     environ[i]   = string;
77     environ[i+1] = NULL;
78     return 0;
79 }
80