src/lib-roff/putenv.c

   1 /*@
   2  * Copyright (c) 2014 - 2015 Steffen (Daode) Nurpmeso <sdaoden@users.sf.net>.
   3  *
   4  * Copyright (C) 1991, 2001, 2006 Free Software Foundation, Inc.
   5  * This file is part of the GNU C Library.
   6  *
   7  * The GNU C Library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Library General Public License as
   9  * published by the Free Software Foundation; either version 2 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * The GNU C Library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Library General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Library General Public
  18  * License along with the GNU C Library; see the file COPYING.LIB.  If
  19  * not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  20  * Cambridge, MA 02139, USA.
  21  */
  22
  23 /* Hacked slightly by jjc@jclark.com for groff. */
  24
  25 #include "config.h"
  26
  27 #include <stdlib.h>
  28 #include <string.h>
  29
  30 typedef void *PTR;
  31 typedef size_t SIZE_T;
  32
  33 extern char **environ;
  34
  35 /* Put STRING, which is of the form `NAME=VALUE', in the environment.  */
  36
  37 int putenv(const char *string)
  38 {
  39   char *name_end = strchr(string, '=');
  40   SIZE_T size;
  41   char **ep;
  42
  43   if (name_end == NULL)
  44     {
  45       /* Remove the variable from the environment.  */
  46       size = strlen(string);
  47       for (ep = environ; *ep != NULL; ++ep)
  48         if (!strncmp(*ep, string, size) && (*ep)[size] == '=')
  49           {
  50             while (ep[1] != NULL)
  51               {
  52                 ep[0] = ep[1];
  53                 ++ep;
  54               }
  55             *ep = NULL;
  56             return 0;
  57           }
  58     }
  59
  60   size = 0;
  61   for (ep = environ; *ep != NULL; ++ep)
  62     if (!strncmp(*ep, string, name_end - string)
  63         && (*ep)[name_end - string] == '=')
  64       break;
  65     else
  66       ++size;
  67
  68   if (*ep == NULL)
  69     {
  70       static char **last_environ = NULL;
  71       char **new_environ = (char **) malloc((size + 2) * sizeof(char *));
  72       if (new_environ == NULL)
  73         return -1;
  74       (void) memcpy((PTR) new_environ, (PTR) environ, size * sizeof(char *));
  75       new_environ[size] = (char *) string;
  76       new_environ[size + 1] = NULL;
  77       if (last_environ != NULL)
  78         free((PTR) last_environ);
  79       last_environ = new_environ;
  80       environ = new_environ;
  81     }
  82   else
  83     *ep = (char *) string;
  84
  85   return 0;
  86 }
  87
  88 // s-it2-mode