1 /*	$NetBSD: unsetenv.c,v 1.1.1.1 2011/04/13 18:15:44 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 #include <string.h>
40 
41 #include <krb5/roken.h>
42 
43 #if !HAVE_DECL_ENVIRON
44 extern char **environ;
45 #endif
46 
47 /*
48  * unsetenv --
49  */
50 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
unsetenv(const char * name)51 unsetenv(const char *name)
52 {
53   int len;
54   const char *np;
55   char **p;
56 
57   if (name == 0 || environ == 0)
58     return;
59 
60   for (np = name; *np && *np != '='; np++)
61     /* nop */;
62   len = np - name;
63 
64   for (p = environ; *p != 0; p++)
65     if (strncmp(*p, name, len) == 0 && (*p)[len] == '=')
66       break;
67 
68   for (; *p != 0; p++)
69     *p = *(p + 1);
70 }
71 
72