crypto/external/bsd/heimdal/dist/lib/roken/unsetenv.c

   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
  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