text: /* Copyright (C) 1992, 1995, 1996, 1997, 2002 Free Software Foundation, Inc.
     This file based on setenv.c in the GNU C Library.
  
     The GNU C Library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public License as
     published by the Free Software Foundation; either version 2 of the
     License, or (at your option) any later version.
  
     The GNU C Library is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Library General Public License for more details.
  
     You should have received a copy of the GNU Library General Public
     License along with the GNU C Library; see the file COPYING.LIB.  If not,
     write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
     Boston, MA 02110-1301, USA.  */
  
  
  /*
  
  @deftypefn Supplemental int setenv (const char *@var{name}, const char *@var{value}, int @var{overwrite})
  @deftypefnx Supplemental void unsetenv (const char *@var{name})
  
  @code{setenv} adds @var{name} to the environment with value
  @var{value}.  If the name was already present in the environment,
  the new value will be stored only if @var{overwrite} is nonzero.
  The companion @code{unsetenv} function removes @var{name} from the
  environment.  This implementation is not safe for multithreaded code.
  
  @end deftypefn
  
  */
  
  #if HAVE_CONFIG_H
  # include <config.h>
  #endif
  
  #define setenv libiberty_setenv
  #define unsetenv libiberty_unsetenv
  
  #include "ansidecl.h"
  #include <sys/types.h> /* For `size_t' */
  #include <stdio.h>     /* For `NULL' */
  
  #include <errno.h>
  #if !defined(errno) && !defined(HAVE_ERRNO_DECL)
  extern int errno;
  #endif
  #define __set_errno(ev) ((errno) = (ev))
  
  #if HAVE_STDLIB_H
  # include <stdlib.h>
  #endif
  #if HAVE_STRING_H
  # include <string.h>
  #endif
  #if HAVE_UNISTD_H
  # include <unistd.h>
  #endif
  
  #define __environ	environ
  #ifndef HAVE_ENVIRON_DECL
  extern char **environ;
  #endif
  
  #undef setenv
  #undef unsetenv
  
  /* LOCK and UNLOCK are defined as no-ops.  This makes the libiberty
   * implementation MT-Unsafe. */
  #define LOCK
  #define UNLOCK
  
  /* Below this point, it's verbatim code from the glibc-2.0 implementation */
  
  /* If this variable is not a null pointer we allocated the current
     environment.  */
  static char **last_environ;
  
  
  int
  setenv (const char *name, const char *value, int replace)
  {
    register char **ep = 0;
    register size_t size;
    const size_t namelen = strlen (name);
    const size_t vallen = strlen (value) + 1;
  
    LOCK;
  
    size = 0;
    if (__environ != NULL)
      {
        for (ep = __environ; *ep != NULL; ++ep)
  	if (!strncmp (*ep, name, namelen) && (*ep)[namelen] == '=')
  	  break;
  	else
  	  ++size;
      }
  
    if (__environ == NULL || *ep == NULL)
      {
        char **new_environ;
        if (__environ == last_environ && __environ != NULL)
  	/* We allocated this space; we can extend it.  */
  	new_environ = (char **) realloc (last_environ,
  					 (size + 2) * sizeof (char *));
        else
  	new_environ = (char **) malloc ((size + 2) * sizeof (char *));
  
        if (new_environ == NULL)
  	{
  	  UNLOCK;
  	  return -1;
  	}
  
        new_environ[size] = (char *) malloc (namelen + 1 + vallen);
        if (new_environ[size] == NULL)
  	{
  	  free ((char *) new_environ);
  	  __set_errno (ENOMEM);
  	  UNLOCK;
  	  return -1;
  	}
  
        if (__environ != last_environ)
  	memcpy ((char *) new_environ, (char *) __environ,
  		size * sizeof (char *));
  
        memcpy (new_environ[size], name, namelen);
        new_environ[size][namelen] = '=';
        memcpy (&new_environ[size][namelen + 1], value, vallen);
  
        new_environ[size + 1] = NULL;
  
        last_environ = __environ = new_environ;
      }
    else if (replace)
      {
        size_t len = strlen (*ep);
        if (len + 1 < namelen + 1 + vallen)
  	{
  	  /* The existing string is too short; malloc a new one.  */
  	  char *new_string = (char *) malloc (namelen + 1 + vallen);
  	  if (new_string == NULL)
  	    {
  	      UNLOCK;
  	      return -1;
  	    }
  	  *ep = new_string;
  	}
        memcpy (*ep, name, namelen);
        (*ep)[namelen] = '=';
        memcpy (&(*ep)[namelen + 1], value, vallen);
      }
  
    UNLOCK;
  
    return 0;
  }
  
  void
  unsetenv (const char *name)
  {
    const size_t len = strlen (name);
    char **ep;
  
    LOCK;
  
    for (ep = __environ; *ep; ++ep)
      if (!strncmp (*ep, name, len) && (*ep)[len] == '=')
        {
  	/* Found it.  Remove this pointer by moving later ones back.  */
  	char **dp = ep;
  	do
  	  dp[0] = dp[1];
  	while (*dp++);
  	/* Continue the loop in case NAME appears again.  */
        }
  
    UNLOCK;
  }
  