text: /*
  FUNCTION
  <<_getenv_r>>---look up environment variable
  
  INDEX
  	_getenv_r
  INDEX
  	environ
  
  ANSI_SYNOPSIS
  	#include <stdlib.h>
  	char *_getenv_r(struct _reent *<[reent_ptr]>, const char *<[name]>);
  
  TRAD_SYNOPSIS
  	#include <stdlib.h>
  	char *_getenv_r(<[reent_ptr]>, <[name]>)
  	struct _reent *<[reent_ptr]>;
  	char *<[name]>;
  
  DESCRIPTION
  <<_getenv_r>> searches the list of environment variable names and values
  (using the global pointer ``<<char **environ>>'') for a variable whose
  name matches the string at <[name]>.  If a variable name matches,
  <<_getenv_r>> returns a pointer to the associated value.
  
  RETURNS
  A pointer to the (string) value of the environment variable, or
  <<NULL>> if there is no such environment variable.
  
  PORTABILITY
  <<_getenv_r>> is not ANSI; the rules for properly forming names of environment
  variables vary from one system to another.  This implementation does not
  permit '=' to be in identifiers.
  
  <<_getenv_r>> requires a global pointer <<environ>>.
  */
  
  /* This file may have been modified by DJ Delorie (Jan 1991).  If so,
  ** these modifications are Copyright (C) 1991 DJ Delorie.
  */
  
  /*
   * Copyright (c) 1987 Regents of the University of California.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms are permitted
   * provided that: (1) source distributions retain this entire copyright
   * notice and comment, and (2) distributions including binaries display
   * the following acknowledgement:  ``This product includes software
   * developed by the University of California, Berkeley and its contributors''
   * in the documentation or other materials provided with the distribution
   * and in all advertising materials mentioning features or use of this
   * software. Neither the name of the University nor the names of its
   * contributors may be used to endorse or promote products derived
   * from this software without specific prior written permission.
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
   * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
   */
  
  #include <stdlib.h>
  #include <stddef.h>
  #include <string.h>
  #include "envlock.h"
  
  extern char **environ;
  
  /* Only deal with a pointer to environ, to work around subtle bugs with shared
     libraries and/or small data systems where the user declares his own
     'environ'.  */
  static char ***p_environ = &environ;
  
  /*
   * _findenv --
   *	Returns pointer to value associated with name, if any, else NULL.
   *	Sets offset to be the offset of the name/value combination in the
   *	environmental array, for use by setenv(3) and unsetenv(3).
   *
   *	This routine *should* be a static; don't use it.
   */
  
  char *
  _DEFUN (_findenv_r, (reent_ptr, name, offset),
          struct _reent *reent_ptr   _AND
  	register _CONST char *name _AND
  	int *offset)
  {
    register int len;
    register char **p;
    _CONST char *c;
  
    ENV_LOCK;
  
    /* In some embedded systems, this does not get set.  This protects
       newlib from dereferencing a bad pointer.  */
    if (!*p_environ)
      {
        ENV_UNLOCK;
        return NULL;
      }
  
    c = name;
    while (*c && *c != '=')  c++;
   
    /* Identifiers may not contain an '=', so cannot match if does */
    if(*c != '=')
      {
      len = c - name;
      for (p = *p_environ; *p; ++p)
        if (!strncmp (*p, name, len))
          if (*(c = *p + len) == '=')
  	{
  	  *offset = p - *p_environ;
  	  ENV_UNLOCK;
  	  return (char *) (++c);
  	}
      }
    ENV_UNLOCK;
    return NULL;
  }
  
  /*
   * _getenv_r --
   *	Returns ptr to value associated with name, if any, else NULL.
   */
  
  char *
  _DEFUN (_getenv_r, (reent_ptr, name),
          struct _reent *reent_ptr _AND
  	_CONST char *name)
  {
    int offset;
  
    return _findenv_r (reent_ptr, name, &offset);
  }
  